3. A 95% confidence interval for the mean age of all registered voters in a city is (46.7, 54.8). a. What was the sample mean from which this confidence interval was constructed? b. What was the margin of error? c. What would happen to the width of the confidence interval if we increase confidence level to 98%?
3. A 95% confidence interval for the mean age of all registered voters in a city...
In a random sample of 100 registered voters, 20 say they plan to vote for Candidate A.Determine a 95% confidence interval for the proportion of all the registered voters who will vote for Candidate A.You are interested in knowing support for candidate by gender to provide strategic advice to candidate B. Suppose your guess based on previous knowledge is that female support for candidate B is around 20 percent, and male support for candidate B is around 50 percent. Suppose...
Confidence Intervals 9. Construct a 95 % confidence interval for the population mean, . In a random sample of 32 computers, the mean repair cost was $143 with a sample standard deviation of $35 (Section 6.2) Margin of error, E. <με. Confidence Interval: O Suppose you did some research on repair costs for computers and found that the population standard deviation, a,- $35. Use the normal distribution to construct a 95% confidence interval the population mean, u. Compare the results....
A pollster wants to find a 95% confidence interval for the proportion of registered voters who support a certain candidate. If her confidence interval has to have a margin of error of at most 5.0%, then what’s the smallest random sample of registered voters she can poll?
100 random samples were taken, and for each random sample we made a 95% confidence interval, about how many of those 100 confidence intervals would actually contain the parameter? Increasing the confidence level (more than one) a increase the width of a confidence interval b increase the probability that the parameter is in the confidence interval c increase the percentage of samples which will create a confidence interval that contains the parameter d Increase the margin of error A...
A 95% confidence interval for μ, the true mean city gas mileage for a particular vehicle is (23.0, 26.0). The sample mean, x¯, and margin of error for this interval are:
Let's say we have constructed a 95% confidence interval estimate for a population mean. Which of the following statements would be correct? A. We expect that 95% of the intervals so constructed would contain the true population mean. B. We are 95% sure that the true population mean lies either within the constructed interval or outside the constructed interval. C. Taking 100 samples of the same size, and constructing a new confidence interval from each sample, would yield five intervals...
Explain what "95% confidence" means in a 95% confidence interval. What does "95% confidence" mean in a 95% confidence interval? A. If 100 different confidence intervals are constructed, each based on a different sample of size n from the same population, then we expect 95 of the intervals to include the parameter and 5 to not include the parameter. B. The probability that the value of the parameter lies between the lower and upper bounds of the interval is 95%....
8. A campaign researcher would like to estimate the proportion of registered voters that will vote for his candidate. He runs a poll each week asking registered voters their candidate preference and calculates a 95% confidence interval to estimate the true proportion of registered voters that will vote for his candidate. On week 39 his confidence interval was (0.52, 0.56). On week 40 (the last week of the campaign) he wants to conduct one final poll. He would like his...
11. [6 points] Using a sample of 100 children, a 95% confidence interval for the proportion of children under the age of 18 who had asthma was constructed to be (0.085,6.23) a) Which of the following would produce a confidence interval which is narrower than the constructed 95% confidence interval? Sample 150 children rather than 100, (Maintain the confidence level at 95%) Sample only 80 children rather than 100, (Maintain the confidence level at 95%) . (b) Which of the...
1. A C level confidence interval is described as what? (3 points) Oan interval computed from a data sample by a method that has the probability C of producing an interval containing the true value of the parameter any interval within the margin of error O an interval with a margin of error C that is also correct C% of the time Oany interval that follows the 68-95-99.7 rules Oan interval computed from a data sample that guarantees that the...