Question 1047800
sample mean = 13
sample SD = 6.9 (Generally rounded to one more decimal point than  Data values have)
Recommend following to check work on sample means and 'corrected' standard deviations.
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95% confidence interval 
Small Sample - We are using the T distribution because 
a)  population standard deviation is not being used
b) n = 16 < 30
use t-value = 2.13
SE = (2.13)(6.9/sqrt(16)) = (2.13)1.725
Round the confidence interval limits to the same number of decimal places as the sample standard deviation
CI = 13 ± SE

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99% confidence interval 
Small Sample
use t-value = 2.95
SE = (2.95)(6.9/sqrt(16)) = (2.95)1.725 = 5.1
Round the confidence interval limits to the same number of decimal places as the sample standard deviation
CI = 13 ± 5.1