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WorksheetsStatProb Lesson 4 Quiz Reviewer (SY 25 - 26)
Total questions: 15
Worksheet time: 24mins
A random sample of 10 students yielded the following grades in math:
90, 93, 85, 77, 88, 80, 78, 83, 95, 90
Assume that the population of math grades is normally distributed. What is a point estimate for the population mean? Do not round off your answer.
(a)
In a local survey, 546 of the 684 respondents indicated support for a ban on household aerosols. In solving for a point estimate for the population proportion, which value is x, which is the number of successes in the sample?
(a)
In a local survey, 546 of the 684 respondents indicated support for a ban on household aerosols. What is the proportion of successes? (3 d. p.)
(a)
In a local survey, 546 of the 684 respondents indicated support for a ban on household aerosols. What is the margin of error for a 95% confidence interval? (3 d. p.)
(a)
In a local survey, 546 of the 684 respondents indicated support for a ban on household aerosols. Interpret the results of the 95% confidence interval for the population proportion of people who support the ban.
With 95% confidence, we can say that the population proportion of people who support the ban on household aerosols is between 76.8% and 82.8%
With 95% confidence, we can say that the population proportion of people who support the ban on household aerosols is between 77.3% and 82.3%
With 95% confidence, we can say that the population proportion of people who support the ban on household aerosols is between 74.8% and 83.8%
With 95% confidence, we can say that the population proportion of people who support the ban on household aerosols is between 76.4% and 83.2%
Does the following situation involve a normal distribution, a t-distribution, or neither? A telecommunications company wants to estimate the mean length of time (in minutes) that 18- to 24-year olds spend browsing their social media accounts each day. In a random sample of thirty-one 18- to 24-year olds, the mean length of time spent browsing their social media accounts was 29 minutes and the standard deviation was 4.5 minutes.
normal distribution
t-distribution
neither
A telecommunications company wants to estimate the mean length of time (in minutes) that 18- to 24-year olds spend browsing their social media accounts each day. In a random sample of thirty-one 18- to 24-year olds, the mean length of time spent browsing their social media accounts was 29 minutes and the standard deviation was 4.5 minutes. What is the margin of error for a 90% confidence interval? (1 d. p.)
(a)
A telecommunications company wants to estimate the mean length of time (in minutes) that 18- to 24-year olds spend browsing their social media accounts each day. In a random sample of thirty-one 18- to 24-year olds, the mean length of time spent browsing their social media accounts was 29 minutes and the standard deviation was 4.5 minutes. What is a 90% confidence interval for the population mean length of time? (1 d. p.)
27.7<μ<30.3
27.4<μ<30.6
26.9<μ<31.1
27.5<μ<30.4
What is the minimum sample size needed to estimate the population mean given the following values: c=0.99, σ=6.8, and E=2.5 ? Round up your answer to the nearest whole number.
71
50
8
29
If there is no preliminary estimate, then what is the minimum sample size needed to estimate the population proportion given the following values: c=0.90 and E=0.05 ? Round up your answer to the nearest whole number.
271
385
664
409
What is the minimum sample size required to have a margin of error of 12 months and a 95% confidence interval for the mean duration of imprisonment of all East German political prisoners with chronic post traumatic stress disorder (PTSD)? Let the sample standard deviation be 42 months. Round up your answer to the nearest whole number.
48
34
82
60
A market research survey will be conducted on consumer preference of laundry soap brands. 138 out of 300 persons preferred the laundry powder Olla. How large a sample is needed if the maximum error must not exceed 3% at the 99% confidence interval? Round up your answer to the nearest whole number.
1,831
747
1,061
529
If the sample size is 29, then what is the degrees of freedom?
28
30
27
31
What is the critical t-value for a 90% confidence level when the degrees of freedom is 19? (3 d. p.)
1.729
1.734
1.725
2.861
In a random sample of 8 people, the mean commute time to work was 35.5 minutes and the sample standard deviation was 7.2 minutes. Assume that population data on the commute time to work is normally distributed. What is the margin of error for a 95% confidence interval? Round off the critical t-value to 3 d. p.
6.2
5.7
5.8
6.0
