To compare the effect of stress caused by noise on the ability to perform a simple task, 74 subjects were divided into two groups-32 subjects as a control group, and 42 subjects as the experimental group. Although each subject performed the task, the experimental group had to perform the task while loud rock music was played. The time to finish the task was recorded for each subject and the following summary was obtained. n x Control 32 17 minutes 5 minutes Experimental 42 25 minutes 11 minutes (a) Find a 99% confidence interval for the difference in mean completion times (in minutes) for these two groups. (Calculate the difference as the control group the experimental group. Round your answers to two decimal places.) min to min (b) Based on the confidence interval in part (a), is there sufficient evidence to indicate a difference in the average time to completion for the two groups? Explain. The confidence interval in part (a) has ---Select--- groups. . Hence, it is ---Select-- that the means are equal. Based on the data we would conclude that ---Select--- a real difference in the mean times to completion for the two

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I need help with all parts of this question 9
The options for part B selection (a) two positive endpoints/one positive and one negative endpoint/two negative endpoints
(b) plauisble/not likely
(c)there is no evidence, there is

To compare the effect of stress caused by noise on the ability to perform a simple task, 74 subjects were divided into two groups—32 subjects as a control group, and 42 subjects as the experimental group. Although each subject performed the task, the experimental group had to perform the task while loud rock music was played. The time to finish the task was recorded for each subject and the following summary was obtained.

|       | Control | Experimental |
|-------|---------|--------------|
| \( n \)   | 32      | 42           |
| \( \bar{x} \) | 17 minutes | 25 minutes   |
| \( s \)   | 5 minutes  | 11 minutes  |

(a) Find a 99% confidence interval for the difference in mean completion times (in minutes) for these two groups. (Calculate the difference as the control group − the experimental group. Round your answers to two decimal places.)

\[ \text{min to} \text{min} \]

(b) Based on the confidence interval in part (a), is there sufficient evidence to indicate a difference in the average time to completion for the two groups? Explain.

The confidence interval in part (a) has \[ \_\_\_\_\] . Hence, it is \[ \_\_\_\_\] that the means are equal. Based on the data we would conclude that \[ \_\_\_\_\] a real difference in the mean times to completion for the two groups.
Transcribed Image Text:To compare the effect of stress caused by noise on the ability to perform a simple task, 74 subjects were divided into two groups—32 subjects as a control group, and 42 subjects as the experimental group. Although each subject performed the task, the experimental group had to perform the task while loud rock music was played. The time to finish the task was recorded for each subject and the following summary was obtained. | | Control | Experimental | |-------|---------|--------------| | \( n \) | 32 | 42 | | \( \bar{x} \) | 17 minutes | 25 minutes | | \( s \) | 5 minutes | 11 minutes | (a) Find a 99% confidence interval for the difference in mean completion times (in minutes) for these two groups. (Calculate the difference as the control group − the experimental group. Round your answers to two decimal places.) \[ \text{min to} \text{min} \] (b) Based on the confidence interval in part (a), is there sufficient evidence to indicate a difference in the average time to completion for the two groups? Explain. The confidence interval in part (a) has \[ \_\_\_\_\] . Hence, it is \[ \_\_\_\_\] that the means are equal. Based on the data we would conclude that \[ \_\_\_\_\] a real difference in the mean times to completion for the two groups.
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