The formula for margin of error is:
As the sample size increases, margin of error decreases.
As the confidence interval increases, critical value increases so margin of error increases. That is decreasing confidence level will decrease the margin of error.
Correct options are: A and F
In a survey conducted by a polling company, 1100 adult Americans were asked how many hours...
In a survey conducted by the Gallup Organization, 1100 adult Americans were asked how many hours they worked in the previous week. Based on the results, a 95% confidence interval for the mean number of hours worked had a lower bound of 42.7 and an upper bound of 44.5. Provide two recommendations for decreasing the margin of error of the interval. Select all that apply. A. Decrease the sample size. B. Increase the sample size. O C. Decrease the standard...
In a survey, 500 adults in a certain country were asked how many hours they worked in the previous week. Based on the results, a 95% confidence interval for mean number of hours worked was lower bound: 37.1 and upper bound: 38.9. Which of the following represents a reasonable interpretation of the result? For those that are not reasonable, explain the flaw. Complete parts (a) through (d) below. (a) There is a 95% chance the mean number of hours worked...
A polling center conducted a survey that asked 1016 adults how many books they'd read in the last year. Results indicated that x baroverx=12.1 books and standard deviation, s, =16.6 books. Construct a 90% confidence interval for the mean number of books people read.
1, In 1943, an organization surveyed 1100 adults and asked, "Are you a total abstainer from, or do you on occasion consume, alcoholic beverages?" Of the 1100 adults surveyed, 385 indicated that they were total abstainers. In a recent survey, the same question was asked of 1100 adults and 363 indicated that they were total abstainers. Complete parts (a) and (b) below. (a) Determine the sample proportion for each sample. The proportions of the adults who took the 1943 survey...
The 2010 General Social Survey asked the question: "After an average work day, about how many hours do you have to relax or pursue activities that you enjoy?" to a random sample of 1155 Americans. A 90% confidence interval for the mean number of hours spent relaxing or pursuing activities they enjoy was [1.17, 1.83]. (a) Interpret this interval in context of the data: "There is a 90% chance that the average number of hours spent by Americans relaxing after...
4. A survey asked a random sample of 363 first-year students how many hours they studied during a particular week. The mean was 15.3 hours. Suppose we know that the population standard deviation is 8.5 hours. Construct a 90%, 95% and 99% confidence interval for the mean study time of all first year students at this university. Interpret the 90% confidence interval.
In a survey of 28 teenagers who were asked how many hours per week they spend watching T.V., the sample mean was 13 hours and the population standard deviation is 5.8 hours. Find a 99% Confidence Interval for the population mean number of hours teenagers watch T.V. Write the interval below. Write a sentence interpreting this. (Round answer to 2 decimal places)
In a survey, 800 managers in a certain city were asked how many hours they worked in the previous week. Using the results, a 90% confidence interval for the mean number of hours worked was constructed: (38.1, 44.3). Which of the following represents the best interpretation of the result? For those that are not correct, explain the flaw. (A) We are 90% confident that the mean number of hours worked by managers in this city in the previous week was...
A survey asked college freshman how far away from their hometown is from the college campus. A random sample of 36 students is taken with a mean distance of 100 miles and a standard deviation of 30 Complete parts (a) and (b) below (a) Find the 95% confidence interval for the population mean Lower bound Upper bound (Round your answer to one decimal place) (b) Suppose you want the estimate to be within 3 miles of the population mean. Determine...
A survey of 675 randomly sampled adults asked how many hours per week each respondent spent watching television. The margin of error was 3 hours per week. The confidence interval was taken at the 95% level. This means that, if the same survey question was repeated in 100 random samples of 675 adults, the results of about 95 of those surveys would be within 3 hours of the results of this survey.