Q1 In a random sample of 18 families, the average weekly food expense was $95.60
ID: 3356805 • Letter: Q
Question
Q1
In a random sample of 18 families, the average weekly food expense was $95.60 with a standard deviation of $22.50. what are the lower limit and upper limit confidence interval values for a 95% confidence level
a. LL: 86.37, UL: 104.83
b. LL: 84.41, UL: 106.79
c. LL: 82.21 UL: 105.99
Q2
If all other quantities remain the same, what affect does increasing the sample size n, have on the width of the confidence interval?
It will widen the confidence interval
It will make the confidence interval more narrow
It will have no affect on the confidence interval
Q3
If all other quantities remain the same, what affect does increasing the standard deviation, have on the width of the confidence interval?
It will widen the confidence interval
It will make the confidence interval more narrow
It will have no affect on the confidence interval
Q4
The parameter that is the result of standard deviation divided by the square root of n, the sample size, is referred to as
A Point Estimate
An Interval Estimate
Level of Confidence
Margin of Error
Standard Error
Q5
Find the critical t value for a 95% confidence interval and a sample size, n, equal to 16
2.947
2.131
2.602
1.753
None of the above
Q6
Find the critical t value for a 90% confidence interval and a sample size, n, equal to 10
2.262
3.25
1.812
1.833
None of the above
It will widen the confidence interval
b.It will make the confidence interval more narrow
c.It will have no affect on the confidence interval
Explanation / Answer
Answer - 1) The statistical software output for this problem is:
One sample T summary confidence interval:
: Mean of population
95% confidence interval results:
Hence,
LL = 84.41
UL = 106.79
Option B is correct.
Answer - 2)
It will make the confidence interval more narrow
Option B is correct.
Answer - 3)
It will widen the confidence interval
Option A is correct.
Answer - 4) Standard Error
Option E is correct.
Mean Sample Mean Std. Err. DF L. Limit U. Limit 95.6 5.3033009 17 84.411013 106.78899Related Questions
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