WorksheetsConfidence Intervals for Means
Total questions: 11
Worksheet time: 3hrs 45mins
A sample of 20 cupcakes found the interval for average calories to be (150, 350). Which is the correct interpretation of the 95% confidence interval?
We are 95% confident that the true mean caloric content can be found with a sample of 150 to 350 cupcakes.
We are 95% confident that the interval (150, 350) captures the true average caloric content.
We are 95% confident that a sample of 20 cupcakes will find 250 calories per cupcake.
None of these are correct.
A sample size of n = 64 is drawn from a population whose standard deviation is σ = 5.6.
Find the margin of error for a 99% confidence interval for µ.
1.799
1.798
1.803
An IQ test was given to a simple random sample of 75 students at a certain college. The sample mean score was 105.2. Scores on this test are known to have a standard deviation of 10. It is desired to construct a 90% confidence interval for the mean IQ scores of the students at the college.
What is the point estimate?
75
105.2
10
0.90
An IQ test was given to a simple random sample of 75 students at a certain college. The sample mean score was 105.2. Scores on this test are known to have a standard deviation of 10. It is desired to construct a 90% confidence interval for the mean IQ scores of the students at the college.
Find the Standard Error.
75
10
105.2
1.155
If the 95% Confidence Interval for a population mean is (114.56, 125.54), then is it likely that the true population mean µ is greater than 130?
Yes
No
Not enough information
I have no idea what you're asking of me
A study found that in a sample of 44 subjects, 9 of agree that children under 6 shouldn’t be taken to nice restaurants.
The 95% confidence interval for p is (0.082, 0.318). Interpret this interval.
95% of the time the proportion of people who believe children under 6 shouldn't be taken to nice restaurants will be between 8.2% and 31.8%.
The population proportion of people who believe children under 6 shouldn't be taken to nice restaurants is between 8.2% and 31.8%.
The probability that the proportion of people who believe children under 6 shouldn't be taken to nice restaurants will be between 8.2% and 31.8% is 95%.
Based on this sample, I am 95% confident that the proportion of people who believe children under 6 shouldn't be taken to nice restaurants is between 8.2% and 31.8%.
Which confidence would result in a wider interval (assuming nothing else changed), 91% or 97%?
97%, z* is larger for higher confidence intervals
97%, the standard error is larger for higher confidence intervals
91%, z* is larger for lower confidence intervals
91%, the standard error is smaller for lower confidence intervals
Does the interval (3, 14) support the claim that the mean of a data set is 2.9
Yes
No
Not enough information.
