Question

Can anyone explain where the 252 came from for the hypotheses?

Example 5: Another made up report ("Stat 1x1 Student Ages") claimed that, "The age of University of Alberta Stat 1x1 students depends on gender." To explore this claim, a poll was conducted by a particular statistics instructor. The results found the following Summary statistics for age (in months): Variance 243.5 2620.582 240.5 1729.273 Mean Std. Dev. gen Female Male 74 51.192 52 41.585 Assuming the individuals were randomly selected from the population, is there any validity to the report? a) Find a 95% confidence interval for the average age of males and females in this population. Males: 240.5 1 {2.009x 5.7668} -> (228.95, 252.12) Females: 243.51{2.000x 5.9509; -> (231.60, 255.40) b) Is the average age for males under 21 years old? Is the average age for females under 21 years old? Answer these questions by carrying out a hypothesis tests with significance level 0.05. Ho : μ-252 vs. H : μ < 252 Males:1.99,p -value (0.025,0.05). (or about 0.026 off a computer) with a p-value of 0.026 we can reject Ho at α-0.05. At α-0.05 we can conclude that HM252 Females:1.43, p-value e (0.05,0.10) (or about 0.078 off a computer) with a p-value of 0.078 we fail to reject Ho at α-o.05. At α-o.05 we can not conclude that Hf <252.

Answer 1

b) bit is related to one sample t test for males and females.

252 is the assumed population mean of the given problem. It is an Hypothetical value.

Now we are testing whether the sample mean age (in months) is significantly less than that population mean or not.

It is a one tailed test.

Simply 252 is the assumed population mean

For males: p<0.05

There is an evidence to alternative hypothesis

For females p>0.05

There is not enough evidence to females.