Question

In a sample of Oscar winning actresses ages, it was found that 82 of them had an average of 35.76 years. The standard deviation of all Oscar winning actresses is 9.54 years. Test the claim that the mean age of actresses, when they win the Oscar, is more than 33 years of age. Use a 5% significance level.

Answer 1

We have:

X→age of actresses

Sample mean (xbar)= 35.76

Sample size (n)= 82

standards deviation (s)= 9.54

Setting up hypothesis:

Ho: u= 33

H1: u>33

Test statistic t= [(xbar-u)/(s/√n)]

=[(35.76-33)/(9.54/√82)]

=2.6198

Thus test statistic= t= 2.6198

Df= 81

Pvalue= prob(t>2.6198)=0.00525

And level of significance (alpha)=5%=0.05

Since p value is less tha 0.05 we Reject the null hypothesis.

Conclusion: we have sufficient evidence to support the claim that mean age of actresses, when they win the Oscar, is more than 33 years of age.

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