A random sample of medical files is used to estimate the proportionpof all people who have blood type B. If you have no preliminary estimate forp, how many medical files should you include in a random sample in order to be 99% sure that the point estimatewill be within a distance of 0.07 fromp?

Group of answer choices

680

1359

19

10

340

2

Suppose thirty-nine communities have an average ofreported cases of larceny per year. Assume thatis known to be 46.9 cases per year. Find a 90%, 95%, and 98% confidence interval for the population mean annual number of reported larceny cases in such communities. Compare the lengths of the confidence intervals. As the confidence levels increase, do the confidence intervals increase in length?

Group of answer choices

The 90% confidence level has a confidence interval length of 4.0; the 95% confidence level has a confidence interval length of 4.7; and the 98% confidence level has a confidence interval length of 5.6. As the confidence level increases, the confidence interval lengths increases.

The 90% confidence level has a confidence interval length of 24.7; the 95% confidence level has a confidence interval length of 29.4; and the 98% confidence level has a confidence interval length of 35.0. As the confidence level increases, the confidence interval lengths increases.

The 90% confidence level has a confidence interval length of 218.6; the 95% confidence level has a confidence interval length of 183.8; and the 98% confidence level has a confidence interval length of 154.3. As the confidence level increases, the confidence interval lengths decreases.

The 90% confidence level has a confidence interval length of 5.6; the 95% confidence level has a confidence interval length of 4.7; and the 98% confidence level has a confidence interval length of 4.0. As the confidence level increases, the confidence interval length decreases.

The 90% confidence level has a confidence interval length of 154.3; the 95% confidence level has a confidence interval length of 183.8; and the 98% confidence level has a confidence interval length of 218.6. As the confidence level increases, the confidence interval length increases.

3

Suppose a random sample of 459 married couples found that 307 had two or more personality preferences in common. In another random sample of 471 married couples, it was found that only 31 had no preferences in common. Letbe the population proportion of all married couples who have two or more personality preferences in common. Letbe the population proportion of all married couples who have no personality preferences in common. Find a 95% confidence interval for

Group of answer choices

0.554 to 0.652

0.555 to 0.651

0.530 to 0.676

0.601 to 0.605

0.529 to 0.677

4

Independent random samples from two regions in the same area gave the following chemical measurements (ppm). Assume the population distributions of the chemical are mound-shaped and symmetric for these two regions.

Region I:;

438 1013 1127 737 491 840 306 402 1155 1075 500 340

Region II:;

778 464 563 610 827 894 476 394 824 387 816 767 479 710 389 826

Letbe the population mean forandbe the population mean for. Find a 90% confidence interval for.

Group of answer choices

-114.49 to 242.99

-253.50 to 125.00

-248.25 to 119.75

-119.75 to 248.25

-125.00 to 253.50

5

Group I nesting boxes were well separated from each other and well hidden by available brush. There were a total of 480 eggs in group I, of which a field count showed about 275 hatched. Group II nesting boxes were placed in highly visible locations and grouped closely together. There were a total of 874 eggs in group II boxes, of which a field count showed about 272 hatched. Find a point estimatefor, the proportion of eggs that hatch in group I nest box placements.

Group of answer choices

0.567

0.311

0.573

0.404

0.315