Question

According to a certain website, the average height for an adult female is 65 inches with a standard deviation of 3.5 inches. Ask 15 people of that gender for their height. (population mean is 63.5 inches from survey of 15 females)

a) What is the null hypothesis and what is the alternative hypothesis?

b) Which test statistic should be used? Why?

c) Perform the appropriate hypothesis test using an alpha level of 0.05. You can use either a p-value or a critical value to perform this test.

d) What conclusion can be drawn about the values for average height on this website for men or women (depending on your choice)?

Answer 1

***it will be sample mean is 63.5 inches from survey of 15 females....not population mean.

given data are:-

sample size (n) = 15

sample mean () = 63.5

population sd ()= 3.5

a).hypothesis:-

where, is the average height on this website for women

b). here, we will use a z test statistic..because , here we know the population sd.

test statistic be:-

c). critical value of z at 95% confidence level be:-

rejection region:-

reject the null hypothesis if,

or  

decision:-

so, we fail to reject the null hypothesis.

d).hence we conclude that,

there is sufficient evidence to support the claim of the website, that, the average height for an adult female is 65 inches

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