Q.84 - The Practice of Statistics for AP

Question

A blogger claims that U.S. adults drink an average of five 8-ounce glasses of water per day. Skeptical researchers ask a random sample of 24 U.S. adults about their daily water intake. A graph of the data shows a roughly symmetric shape with no outliers. The figure below displays Minitab output for a one-sample t interval for the population mean. Is there convincing evidence at the $10\%$ significance level that the blogger’s claim is incorrect? Use the confidence interval to justify your answer. 

Step-by-Step Solution

Answer

There is sufficient proof to infer that case of site is inaccurate at $5\%$ significance level. 

Step 1: Given information

Given in the question that, A blogger claims that U.S. adults drink an average of five -$8$ounce glasses of water per day. Skeptical researchers ask a random sample of$24$ U.S. adults about their daily water intake. A graph of the data shows a roughly symmetric shape with no outliers. The figure below displays Minitab output for a one-sample t interval for the population mean.

We need to find that the blogger’s claim is incorrect at the$10\%$ significance level.

Step 2: Explanation

The output is,

From the above output, the $95\%$  confidence interval is $(3.794,4.615)$. It means that there are $90\%$ chances that typical intake of water is somewhere in the range of $3.794$  and $4.615$. Here, 5 doesn't lie in the registered confidence interval. In this manner, there is sufficient proof to infer that case of site is inaccurate at $5\%$ significance level.