Question

A car manufacturer is going to hire new people to work on an assembly line. The production manager would like to assign new employees to the current team in each station. According to a team performance analysis, following results are available:

New Employee: Sample Size - 49; Average wasting time (minute) - 9; Standard deviation of wasting time (minute) - 4

Experienced Employee: Sample Size - 36; Average wasting time (minute) - 7.5; Standard deviation of wasting time (minute) - 5

With 95% confidence level, can the manager conclude that the average wasting time of the new employees is higher than experienced employees?

Answer 1

In question equality of variances assumption is NOT given.

NULL HYPOTHESIS H0:

ALTERNATIVE HYPOTHESIS Ha:

alpha=0.05

mean wasting time for new employees and mean wasting time for old employees.

Under null hypothesis test statistic

t= xbar-ybar/sqrt(s1^2/n1+s2^2/n2)

t= 9-7.5/sqrt(16/49+25/36)

t= 1.4846

Degrees of freedom= 65

The p-value is .071242. The result is not significant because p > .05.

Decision: DO NOT REJECT H0.

Conclusion: We don't have sufficient evidence to conclude that the average wasting time of the new employees is higher than experienced employees at 0.05 significance level.