Suppose a researcher takes a random sample of 1,000 students from a university and creates a 95% confidence interval for the true proportion of left handed students at the university. Which of the following is true about this interval when compared with a 95% confidence interval based on a random sample of 600 students from the same university?
Suppose a researcher takes a random sample of 1,000 students from a university and creates a 95% confidence interval for the true proportion of left handed students at the university. Which of the following is true about this interval when compared with a 95% confidence interval based on a random sample of 600 students from the same university?
a. The interval based on a sample of 600 students will be wider than the interval based on a sample of 1,000 students.
b. The lower and upper endpoints of the 95% CI based on 600 students will both be larger than the corresponding lower and upper endpoints of the 95% CI based on 1,000 students.
c. 95% CIs based in samples of 1,000 students are more likely to include the true population proportion than 95% CIs based on samples of 600 students.
d. The interval based on a 1,000 students will be wider than the interval based on 600 students.
2. If the researchers above wished to decrease the width of the mean confidence interval for the mean age of MI in the population from which the sample was taken, which of the following actions could they take?
a. Increase the sample size.
b. Use a smaller confidence level (90% for example).
c. Both a and b.
d. Neither a and b.
3. The standard error of a sample mean estimate decreases as:
a. As the sample size on which the mean is based increases.
b. As the number of samples increases.
c. As the sample size on which the mean is based decreases.
d. As the sample standard deviation increases.
Step by step
Solved in 2 steps with 1 images
