In: Statistics and Probability
The following data lists the ages of a random selection of actresses when they won an award in the category of Best Actress, along with the ages of actors when they won in the category of Best Actor. The ages are matched according to the year that the awards were presented. Complete parts (a) and (b) below. Actress left parenthesis years right parenthesis 31 30 31 28 33 23 24 38 33 32 Actor left parenthesis years right parenthesis 67 40 37 36 31 34 55 39 39 40 a. Use the sample data with a 0.01 significance level to test the claim that for the population of ages of Best Actresses and Best Actors, the differences have a mean less than 0 (indicating that the Best Actresses are generally younger than Best Actors). In this example, mu Subscript d is the mean value of the differences d for the population of all pairs of data, where each individual difference d is defined as the actress's age minus the actor's age. What are the null and alternative hypotheses for the hypothesis test? Upper H 0 : mu Subscript d ▼ greater than equals not equals less than nothing year(s) Upper H 1 : mu Subscript d ▼ greater than less than not equals equals nothing year(s) (Type integers or decimals. Do not round.) Identify the test statistic. tequals nothing (Round to two decimal places as needed.) Identify the P-value. P-valueequals nothing (Round to three decimal places as needed.) What is the conclusion based on the hypothesis test? Since the P-value is ▼ greater than less than or equal to the significance level, ▼ fail to reject reject the null hypothesis. There ▼ is is not sufficient evidence to support the claim that actresses are generally younger when they won the award than actors. b. Construct the confidence interval that could be used for the hypothesis test described in part (a). What feature of the confidence interval leads to the same conclusion reached in part (a)? The confidence interval is nothing year(s)less than mu Subscript dless thannothing year(s). (Round to one decimal place as needed.) What feature of the confidence interval leads to the same conclusion reached in part (a)? Since the confidence interval contains ▼ only negative numbers, zero, only positive numbers, ▼ reject fail to reject the null hypothesis.
from above test statistic t =-2.96
p value =0.008
Since the P-value is less than or equal to the significance level reject the null hypothesis.
There is sufficient evidence to support the claim that actresses are generally younger when they won the award than actors
The confidence interval is -22.5 < μd <-0.5
Since the confidence interval contains only negative numbers reject the null hypothesis.