What is the t-value for a 90% confidence interval for the mean if the sample size is 24?
a. 1.984 b. 1.714 c. 2.069 d. 1.96 e. 2.306
In general, when choosing the sample size for estimating a mean, which of the following will result in a smaller margin of error (E)?
a. |
a larger confidence level |
|
b. |
a smaller sample size |
|
c. |
a dozen glazed donuts |
|
d. |
a larger sample size |
|
e. |
a more expensive calculator |
Given That :
Confidence Interval = 90%
N= 24
Degree of Freedom Df = n-1 = 1-24 = 23
,df
t0.1/2 , df = t0.05, 23
From t table
one tail test
t value at df = 23 p=0.05
t value = 1.714
Hence option b is correct
2)
Margin of Error (E) =
To get smaller Margin error we should increase sample size
So answer is a larger sample size
Hence option d is correct
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