Question

In Country​ A, the population mean height for​ 3-year-old boys is

38

inches. Suppose a random sample of 15​ 3-year-old boys from Country B showed a sample mean of

37.1

inches with a standard deviation of

3

inches. The boys were independently sampled. Assume that heights are Normally distributed in the population. Complete parts a through c below.

a.Determine whether the population mean for Country B boys is significantly different from the Country A mean. Use a significance level of 0.05.

b. find the t statistic

c. find the p

Answer 1

We have given,

population mean = 38 inches,

Sample size = 15,

Sample standard deviation = 3 inches,

Sample mean =37.1 inches.

a) Null hypothesis

vs

Alternative hypothesis

b) We can use here t test statistic formula

=-1.16

c) P value is =0.2655 ..............by using TDIST(-1.16,14,2)

P value 0.2655>0.05

Therefore, we fail to reject H0.

We do not have sufficient evidence to say that , the population mean for Country B boys is significantly different from the Country A mean.