You are a researcher studying the health habits of people living in a large rural area. In particular, you are interested in the amount of weight gained early in life.
You want to estimate the population mean of all weight gains for the area's baby girls in their first year. To estimate the population mean of all such weight
gains, you select a random sample of 15 baby girls from this area and you record the weight (in kg) each gained in their first year. Assume the population is
approximately normally distributed.
Based on your sample, follow the steps below to construct a 90% confidence interval of the weight gains in the first year for all the area's baby girls. (If
necessary, consult a list of formulas.)
(a) Click on "Take Sample" to see the results for your random sample.
Take Sample
Sample size:
0
Point estimate:
0
Number of baby girls
4
Sample standard deviation:
0
15
Sample mean
Enter the values of the sample size, the point estimate of the mean, the sample standard deviation, and the critical value you need for your 90%
confidence interval. (Choose the correct critical value from the table of critical values provided.) When you are done, select "Compute".
Standard error:
5.538
Margin of error:
Sample standard
deviation
1.921
X
Confidence
level
S
Critical value