Questions: from a random sample of 15 customers at each branch. Complete parts (a) through (d) below C. Do not reject H0. There is insufficient evidence that the mean waiting time between the two branches differ. D. Reject H0. There is insufficient evidence that the mean waiting time between the two branches differ b. Determine the p-value in (a) and interpret its meaning p-value =0 (Round to three decimal places as needed) Interpret the p-value Choose the correct answer below A. It is the probability the two banks have different population mean waiting times c. In addition to equal variances, what other assumption is necessary in (a)? A. The sample sizes must be equal B. The samples are specifically chosen and not independently sampled C. Both sampled populations are approximately normal D. Both sampled populations are not approximately normal

from a random sample of 15 customers at each branch. Complete parts (a) through (d) below

C. Do not reject H0. There is insufficient evidence that the mean waiting time between the two branches differ.
D. Reject H0. There is insufficient evidence that the mean waiting time between the two branches differ
b. Determine the p-value in (a) and interpret its meaning
p-value =0
(Round to three decimal places as needed)
Interpret the p-value Choose the correct answer below
A. It is the probability the two banks have different population mean waiting times
c. In addition to equal variances, what other assumption is necessary in (a)?
A. The sample sizes must be equal
B. The samples are specifically chosen and not independently sampled
C. Both sampled populations are approximately normal
D. Both sampled populations are not approximately normal
Transcript text: from a random sample of 15 customers at each branch. Complete parts (a) through (d) below C. Do not reject $\mathrm{H}_{0}$. There is insufficient evidence that the mean waiting time between the two branches differ. D. Reject $\mathrm{H}_{0}$. There is insufficient evidence that the mean waiting time between the two branches differ b. Determine the p-value in (a) and interpret its meaning $p$-value $=0$ (Round to three decimal places as needed) Interpret the p-value Choose the correct answer below A. It is the probability the two banks have different population mean waiting times c. In addition to equal variances, what other assumption is necessary in (a)? A. The sample sizes must be equal B. The samples are specifically chosen and not independently sampled C. Both sampled populations are approximately normal D. Both sampled populations are not approximately normal
failed

Solution

failed
failed

Solution Steps

Step 1: Standard Error Calculation

The Standard Error SE SE is calculated using the formula:

SE=s12n1+s22n2=0.31715+0.11915=0.17 SE = \sqrt{\frac{s_1^2}{n_1} + \frac{s_2^2}{n_2}} = \sqrt{\frac{0.317}{15} + \frac{0.119}{15}} = 0.17

Step 2: Test Statistic Calculation

The test statistic t t is computed as follows:

t=xˉ1xˉ2SE=6.0336.4730.17=2.581 t = \frac{\bar{x}_1 - \bar{x}_2}{SE} = \frac{6.033 - 6.473}{0.17} = -2.581

Step 3: Degrees of Freedom Calculation

The degrees of freedom df df are calculated using the formula:

df=(s12n1+s22n2)2(s12n1)2n11+(s22n2)2n21=0.0010.0=23.234 df = \frac{\left(\frac{s_1^2}{n_1} + \frac{s_2^2}{n_2}\right)^2}{\frac{\left(\frac{s_1^2}{n_1}\right)^2}{n_1 - 1} + \frac{\left(\frac{s_2^2}{n_2}\right)^2}{n_2 - 1}} = \frac{0.001}{0.0} = 23.234

Step 4: P-value Calculation

The p-value P P is calculated as:

P=2(1T(t))=2(1T(2.581))=0.017 P = 2(1 - T(|t|)) = 2(1 - T(2.581)) = 0.017

Step 5: Conclusion

Based on the results:

  • The calculated t t -statistic is 2.581 -2.581 .
  • The p-value is 0.017 0.017 .
  • The degrees of freedom are 23.234 23.234 .
  • The critical value at α=0.05 \alpha = 0.05 is 2.068 2.068 .

Since P<0.05 P < 0.05 , we reject the null hypothesis H0 H_0 . There is sufficient evidence that the mean waiting time between the two branches differs.

Step 6: Assumptions

In addition to equal variances, the assumption that both sampled populations are approximately normal is necessary.

Final Answer

The answers to the questions are:

  • The p-value is 0.017 0.017 .
  • We reject H0 H_0 : There is sufficient evidence that the mean waiting time between the two branches differs.
  • The necessary assumption is that both sampled populations are approximately normal.

Thus, the final boxed answers are: P=0.017 \boxed{P = 0.017} Reject H0 \boxed{\text{Reject } H_0} Assumption: Both populations are approximately normal \boxed{\text{Assumption: Both populations are approximately normal}}

Was this solution helpful?
failed
Unhelpful
failed
Helpful