Question

Here are summary statistics for randomly selected weights of newborn girls: n=36, x=3222.2 g, s= 686.7 g. Use a confidence level of 90

Answer 1

To construct a confidence interval for the weights of newborn girls, we can use the formula CI = x ± z * (s / sqrt(n)), where x is the sample mean, z is the z-score for the desired confidence level, s is the sample standard deviation, and n is the sample size. Plugging in the values, we can calculate the confidence interval.

Step-by-step explanation:

To construct a confidence interval, we can use the formula:

CI = x ± z * (s / sqrt(n))

Where:

• x is the sample mean
• z is the z-score corresponding to the desired confidence level
• s is the sample standard deviation
• n is the sample size

In this case, the sample mean x is 3222.2 g, the sample standard deviation s is 686.7 g, and the sample size n is 36. Since the confidence level is 90%, the corresponding z-score is 1.645. Plugging in these values, we can calculate the confidence interval as:

CI = 3222.2 ± 1.645 * (686.7 / sqrt(36))

Simplifying, we get the confidence interval as (3053.99 g, 3390.41 g).