Suppose we observed 120 successes in a random sample of 300 subjects. What is the 98% confidence interval for p (the proportion of successes in the population)?  Select one: a. (0.321, 0.456) b. (-0.456 , -0.321) c. (0.334 , 0.466) d. (-0.428, -0.372)

Tiffany is a manager who needs to fire the worst performing 3% of employees. At her organization, employee performance is a normally distributed variable. Tiffany should fire employees who have a performance score that correspond with a z-score less than or equal to _____

find tc for a 95% confidence level when the sample size is 6.

A researcher selects a sample of 6 men and 11 women. She asks participants to rate the likelihood they would do female-stereotyped jobs (such as nursing or school teaching) on a scale from 1 = not likely at all to 5 = very likely. Men indicated that they would be less likely to do these jobs (M = 2.1) compared with women (M = 4.3). What is the weighted mean for the combined sample of 17 total participants? O O 2.1 4.3 3.2 3.5

a survey is conducted to compare the proportions of men and women whoaccess their bank statements online. Denoting the population propotions by Pm and Pw, a two-proportion z-test is carried out to test Ho: pm = pw against Ha: pm > pw. The values of the test statistic is found to be z = 0.784, and the p-value for the test is found to be 0.216. Which of the following is the correct interpretation of the p-value? a) given that ha is true, the probability of getting a value of z at least as large as 0.784 is 0.216. b) given that ho is true, the probability of getting a value of z at least as large as 0.784 is 0.216. c) given the results of the survey, the probability that Pm > Pw is 0.216. d) given the results of the survey, the probability that Pm = Pw is 0.216. e) none of the above

Tina catches a 14-pound bass.  She does not know the population mean or standard deviation.  So she takes a sample of five friends and they say the last bass they caught was 9, 12, 13, 10, and 10 pounds.  Find the t and calculate a 95% (α = .05) confidence interval.

If [0.64, 0.82] is a confidence interval for the population proportion. Find the value of the point estimator of the population proportion. Select one: O a. 0.73 O b. 0.70 O c. 0.74 O d. 0.72

The claim is that the proportion of adults who smoked a cigarette in the past week is less than 0.35 and the sample statistics include n =1600 subjects with 576 saying that they smoked cigarette in the past week .Find the value of the test statistics ?

A pharmaceutical company makes tranquilizers. It is assumed that the distribution for the length of time they last is approximately normal. Researchers in a hospital used the drug on a random sample of 9 patients. The effective period of the tranquilizer for each patient (in hours) was as follows: 2.5; 2.8; 3.1; 2.3; 2.3; 2.2; 2.8; 2.1; and 2.4.   1.Which distribution should you use for this problem? (Enter your answer in the form z or tdf where df is the degrees of freedom.)    2. Construct a 95% confidence interval for the population mean length of time.  (i) State the confidence interval. (Round your answers to two decimal places.) (     ,     )   (iii) Calculate the error bound. (Round your answer to two decimal places.)

A pharmaceutical company makes tranquilizers. It is assumed that the distribution for the length of time they last is approximately normal. Researchers in a hospital used the drug on a random sample of 9 patients. The effective period of the tranquilizer for each patient (in hours) was as follows: 2.5; 2.9; 3.1; 2.3; 2.3; 2.2; 2.8; 2.1; and 2.4.