Answer:
first one should be SAS
second one should be the third choice
Using the t-distribution to build the 99% confidence interval, it is found that:
- The margin of error is of 3.64.
- The 99% confidence interval for the population mean is (19.36, 26.64).
<h3>What is a t-distribution confidence interval?</h3>
The confidence interval is:

In which:
is the sample mean.
- s is the standard deviation for the sample.
The critical value, using a t-distribution calculator, for a two-tailed 95% confidence interval, with 21 - 1 = 20 df, is t = 2.086.
The other parameters are given as follows:

The margin of error is given by:

Hence the bounds of the interval are:


The 99% confidence interval for the population mean is (19.36, 26.64).
More can be learned about the t-distribution at brainly.com/question/16162795
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Answer:
2160
Step-by-step explanation:
because c is 15 and d is 12 therefore d² is 144 and 144x15 is 2160
Answer:
$2.39
Step-by-step explanation:
to find the cost of 1 pound , divide the cost of 4 pounds by 4
$9.56 ÷ 4 = $2.39
Answer:
answer: he spent $120
Step-by-step explanation:
20×5=100
100+ the initial $20 spent = $120