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Here are summary statistics for randomly selected weight of newborn girls: n=185, x= 31.7 hg, s=6.3 hg. construct a confidence interval estimate of the mean. use a 98% confidence level. Are these results very different from the confidence interval 30.5 hg< u < 32.7 hg with only 19 sample values, x=31.6 hg, and s=1.9 hg?

A) yes, because one confidence interval does not contain the mean of the other confident interval.
B) no because the confidence interval limits are similar.
C) yes because the confidence interval limits are not similar.
D) no because each confidence interval contains the meaning of the other confidence interval.

User Sadiel
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Final answer:

To construct a confidence interval estimate of the mean weight of newborn girls, we can use the formula CI = x ± z * (s / sqrt(n)). Using the given sample mean, standard deviation, and sample size, we can calculate the confidence interval to be (30.624 hg, 32.776 hg) at a 98% confidence level. This confidence interval is not very different from the given confidence interval of (30.5 hg < u < 32.7 hg) with a smaller sample size and slightly different sample mean and standard deviation.

Step-by-step explanation:

In order to construct a confidence interval estimate of the mean, we will use the formula:

CI = x ± z * (s / sqrt(n))

where x is the sample mean, s is the sample standard deviation, n is the sample size, and z is the critical value from the standard normal distribution table.

Using the given information, we can calculate the confidence interval as follows:

Sample mean (x): 31.7 hg

Sample standard deviation (s): 6.3 hg

Sample size (n): 185

Critical value (z) at 98% confidence level: 2.326 (from the standard normal distribution table)

CI = 31.7 ± 2.326 * (6.3 / sqrt(185))

Calculating the confidence interval:

CI = 31.7 ± 2.326 * 0.463

CI = 31.7 ± 1.076

CI = (30.624, 32.776)

The 98% confidence interval estimate of the mean weight of newborn girls is (30.624 hg, 32.776 hg).

Comparing this confidence interval to the given confidence interval of (30.5 hg < u < 32.7 hg) with only 19 sample values, x=31.6 hg, and s=1.9 hg, we can see that these results are not very different. Both confidence intervals overlap, indicating that the means are likely to be similar.

User Ben Hardy
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