A researcher was interested in comparing the heights of women in two different countries. Independent simple random samples of 9 women from country A and 9 women from country B collected data for their heights (in inches). The following 90% confidence interval was obtained for the difference between the mean height of women in country A and the mean height of women in country B. -4.34 in. < μA - μB < -0.03 in What does the confidence interval suggest about the population means?

Null hypothesis:

Alternative hypothesis:

And for this case we can use the confidence interval given by:

And after calculate the 90% confidence interval we got:

So then we see that all the values are negative so then we can conclude that the two means are different and on this case the mean for A seems to be lower than the mean for B at 10% of significance.

Step-by-step explanation:

Data given and notation

represent the mean for the sample A

represent the mean for the sample B

represent the sample standard deviation for the sample A

represent the sample standard deviation for the sample B

sample size selected A

sample size selected B

represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the two means are equal., the system of hypothesis would be:

Null hypothesis:

Alternative hypothesis:

And for this case we can use the confidence interval given by:

And after calculate the 90% confidence interval we got:

So then we see that all the values are negative so then we can conclude that the two means are different and on this case the mean for A seems to be lower than the mean for B at 10% of significance.

36 girls

step-by-step explanation:

the 48 boys is 4 parts of the ratio

divide 48 by 4 to obtain one part of the ratio

= 12 ← 1 part of the ratio

3 parts = 3 × 12 = 36 ← number of girls