In order to test [tex]$H_0: \mu_0=40$[/tex] versus [tex]$H_1: \mu \neq 40$[/tex], a random sample of size [tex][tex]$n=25$[/tex][/tex] is obtained from a normal population with a known [tex]$\sigma=6$[/tex]. The sample mean [tex]\bar{x}[/tex] is 42.3.

Using a TI 83/84 calculator, calculate the P-value with the appropriate hypothesis test.

Use a significance level [tex]\alpha=0.01[/tex] and decide whether to accept or reject [tex]$H_0$[/tex] with a valid reason for the decision.

A. My P-value is greater than [tex]\alpha[/tex], so I reject the null hypothesis.
B. My P-value is greater than [tex]\alpha[/tex], so I accept the null hypothesis.
C. My P-value is less than [tex]\alpha[/tex], so I accept the null hypothesis.
D. My P-value is less than [tex]\alpha[/tex], so I reject the null hypothesis.



Answer :

To test [tex]\( H_0: \mu = 40 \)[/tex] versus [tex]\( H_1: \mu \neq 40 \)[/tex], we are given the following data:

- Population mean under null hypothesis ([tex]\( \mu_0 \)[/tex]): 40
- Sample size ([tex]\( n \)[/tex]): 25
- Population standard deviation ([tex]\( \sigma \)[/tex]): 6
- Sample mean ([tex]\( \bar{x} \)[/tex]): 42.3
- Significance level ([tex]\( \alpha \)[/tex]): 0.01

We need to perform a hypothesis test using a TI 83/84 calculator. Here is the step-by-step solution:

1. Calculate the z-score:
[tex]\[ z = \frac{\bar{x} - \mu_0}{\sigma / \sqrt{n}} \][/tex]

Substituting in the given values:
[tex]\[ z = \frac{42.3 - 40}{6 / \sqrt{25}} = \frac{2.3}{6 / 5} = \frac{2.3}{1.2} \approx 1.92 \][/tex]

2. Calculate the P-value for a two-tailed test:
Using the z-score table or the use of a calculator, find the area under the standard normal curve corresponding to the computed z-score.

The P-value for [tex]\( z \approx 1.92 \)[/tex] is:
[tex]\[ P(\text{value}) \approx 0.055 \][/tex]

3. Decision Rule:
Compare the P-value with the significance level [tex]\(\alpha\)[/tex]:

- If [tex]\( \text{P-value} < \alpha \)[/tex], reject the null hypothesis.
- If [tex]\( \text{P-value} \geq \alpha \)[/tex], do not reject the null hypothesis.

Given:
[tex]\[ \text{P-value} \approx 0.055 \quad \text{and} \quad \alpha = 0.01 \][/tex]

Since [tex]\( 0.055 > 0.01 \)[/tex],

Decision: Accept the null hypothesis.

Reason: The P-value is greater than the significance level. Therefore, there is not enough evidence to reject the null hypothesis.

4. Conclusion:
We conclude that, at the [tex]\( \alpha = 0.01 \)[/tex] significance level, the sample data does not provide sufficient evidence to reject the null hypothesis. Thus, we accept [tex]\( H_0: \mu = 40 \)[/tex].

So the final correct interpretation from the options given would be:
- My P-value greater than a Alpha, so I Accept Null Hypothesis