In: Statistics and Probability
Prior to a set of compensation policy changes at a company 31% of the employees surveyed said that they liked their job very much, 50% said that they liked their job moderately, and the remaining employees said that they were dissatisfied with their job. Now, in a survey of 194 employees, 76 said they liked their job very much, 105 said that they liked their job moderately, and the remaining employees said that they were dissatisfied with their job. When testing (at the 10% level of significance) whether the proportions have changed, what is the critical value? (please round your answer to 3 decimal places)
Ho: proportions have not changed
H1: proportions have changed
Chi square test for Goodness of fit
expected frequncy,E = expected proportions*total
frequency
total frequency= 194
category | observed frequencey, O | expected proportion | expected frequency,E | (O-E)²/E | ||
very much | 76 | 0.3100 | 60.14 | 4.183 | ||
moderately | 105 | 0.5000 | 97 | 0.660 | ||
dissatisfied | 13 | 0.1900 | 36.86 | 15.445 |
chi square test statistic,X² = Σ(O-E)²/E =
20.287
level of significance, α= 0.1
Degree of freedom=k-1= 3 -
1 = 2
Critical value = 4.605 [ Excel function:
=chisq.inv.rt(α,df) ]
since, test stat > critical value, reject Ho