# Question

If the variance of a national accounting examination is 900, how large a sample is needed to estimate the true mean score within 5 points with 99% confidence?

## Answer to relevant Questions

a. z a / 2 for the 99% confidence interval b. z a / 2 for the 98% confidence interval c. z a / 2 for the 95% confidence interval d. z a / 2 for the 90% confidence interval e. z a / 2 for the 94% confidence interval Using Table G, find the values for x2 left and x2 right. a. a = 0.05, n = 12 b. a = 0.10, n = 20 c. a = 0.05, n = 27 d. a = 0.01, n = 6 e. a = 0.10, n = 41 In each case, find an . a. n = 80 and X = 40 b. n = 200 and X = 90 c. n = 130 and X = 60 d. n = 60 and X = 35 e. n = 95 and X = 43 It is believed that 25% of U.S. homes have a direct satellite television receiver. How large a sample is necessary to estimate the true population of homes which do with 95% confidence and within 3 percentage points? How ...The proportion of students in private schools is around 11%.Arandom sample of 450 students from a wide geographic area indicated that 55 attended private schools. Estimate the true proportion of students attending private ...Post your question

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