College

A random sample of 10 independent healthy people showed the body temperatures given below (in degrees Fahrenheit). Test the hypothesis that the population mean is [tex]98.6^{\circ} F[/tex], using a significance level of 0.05.

[tex]
\begin{array}{llllllllll}
98.5 & 98.2 & 99.0 & 96.3 & 98.7 & 98.7 & 97.1 & 99.1 & 98.3 & 97.6
\end{array}
[/tex]

Determine the null and alternative hypotheses. Choose the correct answer below.

A. [tex]H_0: \mu \ \textless \ 98.6[/tex]
B. [tex]H_0: \mu \neq 98.6[/tex]
C. [tex]H_0: \mu = 98.6[/tex]
[tex]H_a: \mu \ \textless \ 98.6[/tex]
D. [tex]H_0: \mu = 98.6[/tex]
E. [tex]H_0: \mu \ \textgreater \ 98.6[/tex]
F. [tex]H_0: \mu = 98.6[/tex]
[tex]H_a: \mu \neq 98.6[/tex]

Check the conditions to see whether the test statistic will follow a t-distribution.

- The sample is random, and the observations are independent.
- The distribution of the population is approximately Normal.

Find the test statistic. (Round to two decimal places as needed.)

[tex]\square[/tex]

Answer :

To solve this problem, we need to test the hypothesis regarding the mean body temperature of a population based on a sample. Here is how you can approach the problem step-by-step:

### Step 1: Set the Hypotheses

We need to determine the null and alternative hypotheses:
- Null Hypothesis ([tex]\(H_0\)[/tex]): The population mean [tex]\(\mu\)[/tex] is equal to 98.6°F.
- Alternative Hypothesis ([tex]\(H_a\)[/tex]): The population mean [tex]\(\mu\)[/tex] is not equal to 98.6°F.

Thus, we choose:
[tex]\(H_0: \mu = 98.6\)[/tex]
[tex]\(H_a: \mu \neq 98.6\)[/tex]

This corresponds to a two-tailed test.

### Step 2: Check Conditions

Before proceeding with the t-test, we should confirm the conditions:
- The sample is random, and the observations are independent.
- The distribution of the population is approximately Normal.

Since these conditions are mentioned as fulfilled in the problem, we can proceed with the t-test.

### Step 3: Calculate the Test Statistic

1. Sample Data:
The sample consists of body temperatures:
[tex]\[ 98.5, 98.2, 99.0, 96.3, 98.7, 98.7, 97.1, 99.1, 98.3, 97.6 \][/tex]

2. Sample Size ([tex]\(n\)[/tex]):
The sample size is 10.

3. Sample Mean ([tex]\(\bar{x}\)[/tex]):
Calculate the mean of the sample data.

4. Sample Standard Deviation ([tex]\(s\)[/tex]):
Calculate the standard deviation of the sample using Bessel's correction ([tex]\(ddof=1\)[/tex]).

5. Calculate the t-statistic:
Use the formula:
[tex]\[ t = \frac{\bar{x} - 98.6}{s/\sqrt{n}} \][/tex]

The calculation results in a t-statistic of approximately [tex]\(-1.59\)[/tex].

### Conclusion

With the calculated t-statistic in hand, you can compare it to the critical t-value from the t-distribution table (based on the degree of freedom [tex]\(n-1\)[/tex] and the significance level 0.05) to conclude whether to reject or fail to reject the null hypothesis. Since the problem only asks us to find the test statistic, we stop here. The correct choice of hypotheses based on the given options is:

F. [tex]\(H_0: \mu = 98.6\)[/tex], [tex]\(H_a: \mu \neq 98.6\)[/tex].

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