Question
In: Statistics and Probability
A random sample of 20 subjects was asked to perform a given task. The time in...
A random sample of 20 subjects was asked to perform a given task. The time in seconds it took each of them to complete the task is recorded below:
|
49, 26, 46, 40, 37, 39, 33, 47, 31, 35, 39, 43, 28, 38, 41, 29, 38, 34, 45, 41 |
If we assume that the completion times are normally distributed, find a 95% confidence interval for the true mean completion time for this task. Then complete the table below.
Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place.
What is the lower limit of the confidence interval?
What is the upper limit of the confidence interval?
Solutions
Expert Solution
We have for given data,
Sample mean =37.95
Sample standard deviation =6.444
Sample size =20
Level of significance= 1-0.95=0.05
Degree of freedom =19
t critical value is (by using t table)=
2.093
Confidence interval formula is
=(34.934,40.966)
Lower confidence limit=34.9
Upper confidence limit= 41.0
orchestra answered 1 year agoRelated Solutions
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