IDNLearn.com: Your go-to resource for finding expert answers. Our platform is designed to provide trustworthy and thorough answers to any questions you may have.

A data set includes 110 body temperatures of healthy adult humans with a mean of [tex]$98.0^{\circ} F$[/tex] and a standard deviation of [tex]$0.74^{\circ} F$[/tex]. Construct a [tex]$99\%$[/tex] confidence interval estimate of the mean body temperature of all healthy humans. What does the sample suggest about the use of [tex]$98.6^{\circ} F$[/tex] as the mean body temperature?

What is the confidence interval estimate of the population mean [tex]$\mu$[/tex]?
[tex]$
\square^{\circ} F \ \textless \ \mu \ \textless \ \square^{\circ} F
$[/tex]
(Round to three decimal places as needed.)


Sagot :

To construct a 99% confidence interval for the mean body temperature of all healthy humans, we need to follow these steps:

1. Identify the given data:
- Sample size (\(n\)) = 110
- Sample mean (\(\bar{x}\)) = 98.0°F
- Sample standard deviation (\(s\)) = 0.74°F
- Confidence level = 99%

2. Determine the degrees of freedom (df):
- Degrees of freedom (\(df\)) = \(n - 1\) = 110 - 1 = 109

3. Find the t-critical value:
- For a 99% confidence level and 109 degrees of freedom. Based on tabulated values or computational tools, we find the t-critical value (\(t_{\alpha/2}\)) to be approximately 2.622.

4. Calculate the margin of error (ME):
- The formula for the margin of error is:

[tex]\[ \text{ME} = t_{\alpha/2} \times \left(\frac{s}{\sqrt{n}}\right) \][/tex]

- Plug in the values:

[tex]\[ \text{ME} = 2.622 \times \left(\frac{0.74}{\sqrt{110}}\right) \][/tex]

- Calculate the standard error (SE):

[tex]\[ \text{SE} = \frac{0.74}{\sqrt{110}} \approx 0.0704 \][/tex]

- Now, calculate the margin of error:

[tex]\[ \text{ME} \approx 2.622 \times 0.0704 \approx 0.185 \][/tex]

5. Construct the confidence interval:
- The lower limit of the confidence interval is:

[tex]\[ \text{Lower limit} = \bar{x} - \text{ME} = 98.0 - 0.185 \approx 97.815 \][/tex]

- The upper limit of the confidence interval is:

[tex]\[ \text{Upper limit} = \bar{x} + \text{ME} = 98.0 + 0.185 \approx 98.185 \][/tex]

6. State the confidence interval:
- The 99% confidence interval for the mean body temperature of all healthy humans is approximately:

[tex]\[ 97.815^\circ F < \mu < 98.185^\circ F \][/tex]

Interpretation about the use of \(98.6^\circ F\):

Considering the constructed confidence interval of [tex]\(97.815^\circ F < \mu < 98.185^\circ F\)[/tex], we observe that 98.6°F is not within this interval. This suggests that the traditional average body temperature of 98.6°F might not be an accurate estimate of the mean body temperature for healthy humans based on the provided sample.
Thank you for participating in our discussion. We value every contribution. Keep sharing knowledge and helping others find the answers they need. Let's create a dynamic and informative learning environment together. Thank you for visiting IDNLearn.com. We’re here to provide clear and concise answers, so visit us again soon.