You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately o = confident that your esimate is within 4 of the true population mean. How large of a sample size is required? 49.4. You would like to be 90% n = Do not round mid-calculation. However, use a critical value accurate to three decimal places -this is important for the system to be able to give hints for incorrect answers. Submit Question

You want to obtain a sample to estimate a population proportion. Based on previous evidence, you believe the population proportion is approximately p = 0.62. You would like to be 99% confident that your esimate is within 2% of the true population proportion. How large of a sample size is required? n=

You want to obtain a sample to estimate a population proportion. Based on previous evidence, you believe the population proportion is approximately p = 0.67. You would like to be 90% confident that your esimate is within 5% of the true population proportion. How large of a sample size is required? n =

A survey of 200 senior citizens was undertaken and it was found that 26 of them had the flu vaccine this year. Do these data suggest that the proportion of senior citizens who get the flu vaccine is significantly less than 21 % ? Test at a = 0.10. Round your answers to three decimal places, and round any interim calculations to four decimal places. What is the test statistic? -2.7778 Using your answer from the previous question, find the p-value. .0027 What is the critical value for this test? Part 2 of 3

You want to obtain a sample to estimate a population proportion. Based on previous evidence, you believe the population proportion is approximately p = 0.42. You would like to be 97% confident that your esimate is within 2% of the true population proportion. How large of a sample size is required?  n =

You are a consumer psychologist interested in holiday spending. A national census reports that the American family spent an average of µ = $81 for Halloween candy and costumes last year. A sample of N = 16 families this year produced a mean of $85 with s = 20. t-value ? t-critical?

You want to estimate the average weight in tons of loads carried by trucks through a particular stretch of road. From previous information the standard deviation is expected to be o-13.5 tons. How many trucks must be weighed to estimate the the tons per truck to within 5 tons at a 90% level of confidence. Round your answer up to the largest whole number. n= trucks