OPINION OF THE COURT
ROSENN, Circuit Judge.In this appeal Carolyn Mazus claims she was a victim of sex discrimination and that her first amendment rights were violated when the Pennsylvania Department of Transportation (PennDOT or Department) delayed in offering her a position as a highway maintenance worker. We agree with the district court and hold that Mazus sustained no violation to her rights.
I.
During part of and prior to 1974, the hiring of non-Civil Service Employees by PennDOT, whether male or female, was done under Pennsylvania’s time-hallowed “patronage” system and not controlled by the Department. In Pike County the system operated as follows: PennDOT’s personnel officer in Harrisburg advised the Governor’s personnel representative of a vacancy after learning about it from a county office. The Governor’s personnel representative would notify the local county chairman of the Governor’s political party and forward a job application. The application then would be delivered by the chairman or his designee to the selected candidate or to PennDOT’s county office in Milford. The county chairman issued only one application for each vacancy. The county chairman attempted to fill the job with a person residing in the township where the position was vacant.
From 1971 until the present, PennDOT has been operating under severe budgetary limitations. When a person with a field position left the Department that position was abolished. Thus, PennDOT’s total complement had been reduced from 22,000 in 1971 to 17,000 in November of 1977. From 1971 to November of 1977, only 22 people were hired for Highway Maintenance Worker positions in Pike County.
In July 1974, the Secretary of Transportation informed. Pike County Chairman Ernest Gastmeyer that some highway mainte*872nance men would be hired in the coming fall of that year. Because of the scarcity of highway job openings since 1971, Gastmeyer had decided who would receive them and where they might be assigned.
In October 1974, PennDOT voluntarily initiated an affirmative action program which is the genesis of this proceeding. Appellant’s husband, Daniel, a Department employee working in Pike County, received with his paycheck a flyer promoting affirmative action by encouraging employees to suggest to minority and female acquaintances that they apply for PennDOT jobs. Mrs. Mazus, unemployed at the time, asked her husband to obtain an application from the County Superintendent, Leonard Coddington. Mr. Mazus asked Coddington in November 1974 for such an application but Coddington was unable to obtain one. Mrs. Mazus decided to seek an application directly by the procedures suggested in the flyer. She made several trips to the PennDOT county and district offices but was always turned down. She was ridiculed by Penn-DOT managers at these offices who on a personal basis seemed to feel it was beneath the dignity of a woman to labor on the roads. The district court, however, found that these managers had no hiring authority-
On November 20, 1974 Mrs. Mazus communicated directly with Gastmeyer, the Pike County Democratic Chairman, who told her there were no openings for road workers. Because Mrs. Mazus wished to place an application on file should openings develop, she arranged to meet Gastmeyer at his home at 5:00 P.M. that day. When Mrs. Mazus arrived, Gastmeyer was not there. Mazus never contacted Gastmeyer again.
In late November and December 1974, PennDOT hired nine men as Highway Maintenance Workers. The district court found that all of these men had been seeking a position with the Department for some time prior to Mrs. Mazus.
On November 29,1974, Mrs. Mazus filed a charge with the EEOC alleging that Penn-DOT engaged in sex discrimination in failing to hire her. On April 2, 1975, Mazus obtained an application from the Governor’s Personnel Office, through the assistance of John Harhigh, the Department’s Personnel Coordinator. Harhigh told Coddington that the failure to consider a female applicant was contrary to Departmental policy and informed him that Mrs. Mazus should be hired for the next job that became available. Accordingly, PennDOT hired Mazus and she started working as a highway maintenance worker in May 1977. Meanwhile, on November 7, 1975, EEOC issued its determination that there was reasonable cause to believe that Mrs. Mazus was denied the opportunity during 1974 to apply for a highway maintenance job on the basis of her sex and reasonable cause to believe that PennDOT discriminates against women as a class in hiring.
Mrs. Mazus brought suit in the district court under 42 U.S.C. § 1983 and Title VII of the 1964 Civil Rights Act, for compensatory and punitive damages as well'as injunctive relief alleging that the Department’s patronage hiring, system was unconstitutional and that she was the victim of PennDOT’s discriminatory hiring practices. She sought class certification for her claims. After trial, Chief Judge Nealon held that because Mrs. Mazus was not denied political rights, the hiring system was not unconstitutional. Mazus’ motion for class certification was denied.
To prove a prima facie case of sex discrimination, Mazus introduced federal census data of the classification “laborers — except farm” which showed women comprising 7.6 percent of that category. PennDOT employed only six women as laborers or only 0.17 percent. The Department, however, introduced evidence of statistics from the Pennsylvania Bureau of Employment which showed that women comprise only .51 percent of the available personnel in the relevant category. Judge Nealon concluded that the census statistics and other evidence did not establish a prima facie case of sex discrimination. In the alternative, Judge Nealon found that even if a prima facie case been made out, it had been sufficiently rebutted by PennDOT’s evidence that the *873jobs were assigned to persons who had applied prior to the plaintiff. Mrs. Mazus appeals.
II.
Appellant’s first contention is that Penn-DOT’s hiring system was an unconstitutional patronage system under Elrod v. Burns, 427 U.S. 347, 96 S.Ct. 2673, 49 L.Ed.2d 547 (1976). In Elrod, the Court considered whether employees who allege that they were discharged or threatened with discharge solely because of their political affiliation or nonaffiliation state a claim for deprivation of constitutional rights secured by the first and fourteenth amendments. The plaintiffs claimed they were discharged or threatened with discharge solely for the reason they were not affiliated with or sponsored by the Cook County Democratic Party. In a plurality opinion, the Court concluded that the allegations of patronage terminations, if true, impermissibly constrained an individual’s ability to act according to his beliefs and associate with others and therefore violated the first amendment.1
The Supreme Court has not considered whether Elrod applies to patronage hirings as well as firings. In Rosenthal v. Rizzo, 555 F.2d 390 (3d Cir.), cert. denied, 434 U.S. 892, 98 S.Ct. 268, 54 L.Ed.2d 178 (1977), this court considered the constitutionality of a political discharge of a Philadelphia employee. In dicta, the court stated:
In general, a state may not condition hiring or discharge of an employee in a way which infringes his right of political association. E. g., Keyishian v. Board of Regents, 385 U.S. 589, 87 S.Ct. 675, 17 L.Ed.2d 629 (1967); Elrod v. Burns, 427 U.S. 347, [9]6 S.Ct. 2673, 49 L.Ed.2d 547 (1976).
Id. at 392.
Mrs. Mazus argues that Rosenthal creates a cause of action in this circuit for patronage hirings. Although the language of Rosenthal clearly covers patronage hirings it is pure dicta and not binding on this court. We do not believe it is necessary in this case to determine whether such a cause of action exists2 because, assuming arguendo a cause of action for patronage hiring, Mazus failed to prove sufficient facts. The key to Elrod and its progeny is the interference with political rights and political association. The district court concluded “that plaintiff’s failure to obtain an application and appointment as a highway maintenance worker was [not] conditioned in- any way which infringed her right of political association.” The only proof offered by Mazus was that she had to see the county chairman to pick up a job application. She went to see the chairman once and missed him. There is no evidence as to what political views or affiliations Mazus addresses. There is no evidence that any of Mazus’ activities were chilled in any manner. There is no evidence that the county chairman required a pledge of allegiance or support to any political party from Mazus or that he considered her political affiliation in acting on her application. Finally, there is no evidence that the jobs went to only members of one political party. In sum, there is no first amendment violation because there is no evidence that the job was conditioned on the surrender of any political rights or the right of political association.
III.
Mazus’ second contention is that the district court erred in concluding she failed to *874make out a prima facie case of sex discrimination. In McDonnell Douglas Corp. v. Green, 411 U.S. 792, 802, 93 S.Ct. 1817, 1824, 36 L.Ed.2d 668 (1973), the Court said that a Title VII plaintiff could demonstrate a prima facie case of discrimination by showing:
(1) that he belongs to a [group protected by the statute]; (ii) that he applied and was qualified for a job for which the employer was seeking applicants; (iii) that, despite his qualifications, he was rejected; and (iv) that, after his rejection, the position remained open and the employer continued to seek applicants from persons of complainant’s qualifications.
The district court concluded that (iv) above was not present because Mazus was not denied a position that was available to others. The court found as a fact that the only people hired after Mazus applied were individuals who had been waiting much longer than Mazus for the position to become available. The court further found that after Mazus filed her application she was given the first available position. Even if a prima facie case had been made out, the court held that it had been sufficiently rebutted by PennDOT’s evidence that the jobs had been assigned to persons who had applied prior to Mrs. Mazus. Mazus does not argue that under the facts found by the district court she did in fact make a prima facie showing of discrimination.3 Rather, she claims the district court erred in failing to accept her statistical evidence as establishing a prima facie case of discrimination.
In Hazelwood School District v. United States, 433 U.S. 299, 307-08, 97 S.Ct. 2736, 2741, 53 L.Ed.2d 768 (1977), the Court stated “[w]here gross statistical disparities can be shown, they alone may in a proper case constitute prima facie proof of a pattern or practice of discrimination.” Mazus presented census data evidence to the district court. The data from 1970 census figures, entitled “laborers — except farm,” showed that women comprised 7.6 percent of the laborer positions in Pennsylvania. Mazus argues that the census data was sufficient to establish a prima facie case. The district court believed this category was overbroad and chose to rely more heavily on the State Bureau of Employment Security (BES) data. BES keeps records on job classifications of individuals. One classification is number “899884” which the district court found encompasses occupations including, and similar to, that of highway maintenance men. From January 1, 1975 to September 30, 1977, the number of females assigned to number 899884 varied from 0.41% to 0.68%. Code 899884 consists of
Bondactor, machine operator, chimney repairman, diver helper; then the subgroup in that field lists bellman, diver assistant, diver tender, lifeline tender, hose tender, then in highway maintenance: highway maintenance man, highway patrolman, snowplow operator, turck [sic], snowplow tractor operator, house trailer lot utility man, maintenance man house trailer, maintenance man helper, factory or mill, general maintneance [sic] helper, mobile home repairman, serviceman house trailers, pipeline, sewer pipe cleaner, electric cewer [sic] cleaning machine operator, shaft man; in the mining and quarrying industry: maintenance man, shaft mechanic, shaft repairman, shaft tender, towel cabinet repairman, and window repairman.
Joint App. 25-26 (emphasis supplied).
*875It appears that both the BES statistics and the “laborers — except farm” categories are less than perfect. The BES statistics include certain occupations which appear less likely to draw women than a road maintenance worker. However, the census figures leave much to be desired because we agree with the district court that the category is overbroad, including many types of “inside” workers such as clerical workers, and a number of unrelated jobs. Therefore, the census figures would tend to overstate the number of women interested in employment analogous to highway maintenance work.
Statistical comparisons, if they are to have any value, must be between comparable groups and free from variables which would undermine the reasonableness of discrimination inferences to be drawn. Swint v. Pullman Standard, 539 F.2d 77, 97 n.50 (5th Cir. 1976). Such evidence must be critically examined and all facts and circumstances must be considered. Hester v. Southern Ry., 497 F.2d 1374 (5th Cir. 1974); Logan v. General Fireproofing Co., 521 F.2d 881 (4th Cir. 1971).
The district court concluded that the statistical data failed to establish a prima facie case. We do not believe this finding can be characterized as erroneous in light of the other evidence. The district court found, from the unrebutted testimony of PennDOT’s Personnel Director, that few women actually sought a road maintenance position with the Department. The Pike County Superintendent for many years testified that, in his memory, Mrs. Mazus was the only woman known ever to have sought the road maintenance job. The district court also apparently found, based on all the evidence before it, that Mazus’ statistical source did not accurately reflect the percentage of females interested in the work force in question and thus did not establish a prima facie case. We find no basis to reverse that decision. In any event, a finding that a prima facie case was met would not alter the outcome of the case because the district court found that even if a prima facie case had been made out, it was sufficiently rebutted by PennDOT with evidence that the jobs were assigned without regard to gender to applicants who applied before Mrs. Mazus.4
IV.
Mazus’ final argument is that the district court erred in failing to certify her action as a class action. Despite our resolution of the merits, two recent cases' indicate that Mazus has standing to appeal the denial of class certification and that such an appeal is not moot. In United States Parole Commission v. Geraghty, 445 U.S. 388, 100 S.Ct. 1202, 63 L.Ed.2d 479 (1980), the plaintiff, who was challenging parole guidelines, was released from prison, making his individual claim moot. The Supreme Court concluded that he still had a sufficient “personal stake” in class certification to satisfy the case or controversy requirement of article III.- The Court stated:
Although the named representative receives certain benefits from the class nature of the action, some of which are regarded as desirable and others as less so, these benefits generally are by-products of the class action device. In order to achieve the primary benefits of class suits, the Federal Rules of Civil Procedure give the proposed class representative the right to have a class certified if the requirements of the rules are met.
The imperatives of a dispute capable of judicial resolution are sharply presented issues in a concrete factual setting and self-interested parties vigorously advocating opposing positions. . . . We conclude that these elements can exist with respect to the class certification issue notwithstanding the fact that the *876named plaintiffs claim on the merits has expired.
Id. at 403, 100 S.Ct. at 1212 (footnotes and citations omitted).
In Alexander v. Gino’s, Inc., 621 F.2d 71 (3d Cir. 1980), the court interpreted Geraghty to allow an individual to seek review of a denial of class certification even though the individual was unsuccessful on the merits.
The district court denied the motion for class certification under the following rationale:
3. Plaintiff has renewed her motion for class certification. The reasons given for denying the motion initially continue to apply: there has been no showing that the class includes anyone but plaintiff and the numerosity requirement has been satisfied. Additionally, plaintiff has not demonstrated common questions of law or fact, or that the defendants have acted or refused to act on grounds generally applicable to the class. There has been no evidence that any other person has allegedly been subjected to similar treatment except for Census Bureau statistics which are unpersuasive.
The most significant reason advanced by the district court appears to be that Mazus failed to establish a class because the numerosity requirement could not possibly be satisfied.
The district court has a good deal of discretion in determining whether or not to certify a class. Walton v. Eaton Corp., 563 F.2d 66, 74-75 (3d Cir. 1977); Jones v. Diamond, 519 F.2d 1090, 1100 (5th Cir. 1975). In this case there was no evidence that any other female ever applied for a roadworker job with PennDOT and was rejected. The statistical evidence is ambiguous at best. In sum, there was no evidence from which this court can conclude that the district court abused its discretion in failing to certify a class.
V.
We conclude that the district court did not err in denying the relief sought by Mazus and therefore the judgment of the district court will be affirmed.
Costs taxed to the appellant.
. In Branti v. Finkel, 445 U.S. 507, 100 S.Ct. 1287, 63 L.Ed.2d 574 (1980), the Court recently reaffirmed Elrod, holding that Rockland County Assistant Public Defenders could not be discharged solely because of their political affiliation. The Court stated that political affiliation can only be a factor in a discharge where the affiliation is an appropriate requirement for the effective performance of the office.
. In Shakman v. Democratic Organization of Cook County, 481 F.Supp. 1315 (N.D.Ill.1979), the court held that patronage hirings violated the first amendment because the hirings had the political effect of helping elect regular Democrats and defeating their opponents.
. The dissent suggests that the district court erred in failing to find a prima facie case because there was insufficient evidence to support the assertion that jobs were assigned according to the date of application. However, the district court found “that at the time plaintiff first inquired of Gastmeyer about a highway maintenance position, all had been spoken for and her gender played no part in the fact that she was not selected.” Mrs. Mazus never argued that the district court’s factual findings were “clearly erroneous” or that a prima facie case had been made out on her interpretation of the facts. Mrs. Mazus only argues on this appeal that a prima facie case was made out based on the statistical data. We may not engage in factfinding on this appeal and we must conclude that the finding of the district court that the jobs were assigned to individuals who had applied prior to plaintiff is not “clearly erroneous.”
. The dissent conciudes that Mrs. Mazus was the victim of sex discrimination even though it asserts that the reason she was not hired was “because she did not have the requisite political connections.” At 879. We believe the record fails to show either “disparate treatment” or “disparate impact” on the basis of gender and therefore we do not find a violation of Title VII.