1 sample t-test
[tex]\mu=the\text{ true mean lifetime of new AAA batteries}[/tex][tex]\begin{gathered} H_0\colon\mu=45\text{ hours} \\ H_a\colon\mu>45\text{ hours} \end{gathered}[/tex][tex]n=50[/tex]B)
Calculating t test statistic
[tex]\begin{gathered} t=\frac{statistic-parameter}{s\tan dard\text{ deviation of statistic}} \\ t=\frac{\bar{x}-\mu_0}{\frac{s_x}{\sqrt[]{n}}} \end{gathered}[/tex]Plugging in the values, we have:
[tex]\begin{gathered} t=\frac{\bar{x}-\mu_0}{\frac{s_x}{\sqrt[]{n}}} \\ t=\frac{46.9-45}{\frac{4.6}{\sqrt[]{50}}} \\ t=\frac{1.9}{0.6505} \\ t=2.9207 \end{gathered}[/tex]C)t test statistic = 2.9207
degrees of freedom = n - 1 = 50 - 1 = 49
Using a calculator, we can calculate the p-value.
[tex]p-\text{value}=0.002633[/tex]D)Since p value is less than significance level (p value < alpha), then we will reject H_0 and take the alternate hypothesis.
Thus the test suggests that the new batteries do last more than 45 hours.
E)
We could've done Type I error here.
Type I error or α: Reject the null when it’s true.