Activity 9: Required sample sizes for hypothesis tests Sample size determination is the act of choosing...
Sample size determination is the act of choosing the number of observations or replicates to include in a statistical sample. It is the act of choosing the number of observations or replicates to include in a statistical sample. The sample size is an important feature of any empirical study in which the goal is to make inferences about a population from a sample. In practice, the sample size used in a study is determined based on the expense of data...
A high-tech company wants to estimate the mean number of years of college education its employees have completed. A good estimate of the standard deviation for the number of years of college is 1.32. How large a sample needs to be taken to estimate u to within 0.57 of a year with 95% confidence? (Round you answer up to the nearest whole number.) You may need to use the appropriate table in Appendix B to answer this question.
Use the given information to find the minimum sample size required to estimate an unknown population mean μ. How many business students must be randomly selected to estimate the mean monthly earnings of business students at one college? We want 95% confidence that the sample mean is within $131 of the population mean, and the population standard deviation is known to be $529.
Use the given information to find the minimum sample size required to estimate an unknown population mean mu. How many business students must be randomly selected to estimate the mean monthly earnings of business students at one college? We want 95% confidence that the sample mean is within $ 129 of the population mean, and the population standard deviation known to be $595.
2. At a computer manufacturing company, the actual size of computer chips is uormally^ distributed with a mean of 10 centimeter and a standard deviation of 2.1 centimeter. A random sample of 24 computer chips is taken. What is the probability that the sample mean will be between 10.95 and 11.05 centimeters? The personnel director of a large corporation wants to study absenteeism among clerical workers at the corporation's central office during the year. A random sample of 25 clerical...
SHOW HOW TO FIND THE SAMPLE SIZE WITH TI 83 STEPS An IQ test is designed so that the mean is 100 and the standard deviation is 21 for the population of normal adults. Find the sample size necessary to estimate the mean IQ score of statistics students such that it can be said with 95% confidence that the sample mean is within 7 IQ points of the true mean Assume a :21 and determine the required sample size using...
Determine the minimum sample size required when you want to be 90% confident that the sample mean is within one unit of the population mean and sigma=19.3. Assume the population is normally distributed. A 90 % confidence level requires a sample size of nothing. (Round up to the nearest whole number as needed.)
An admissions director wants to estimate the mean age of all students enrolled at a college. The estimate must be within 1.5 years of the population mean. Assume the population of ages is normally distributed. (a) Determine the minimum sample size required to construct a 90% confidence interval for the population mean. Assume the population standard deviation is 1.6 years. (b) The sample mean is 20 years of age. Using the minimum sample size with a 90% level of confidence,...
9. Suppose that a milk producer wishes to estimate the mean shelf life (in days) of one-gallon cartons of milk. The population standard deviation is known from past studies. If the manufacturer wishes to be 95% confident of getting an estimate within 2 days of the true mean shelf life, what was the standard deviation (0) if the required sample size is 138.3 before rounding up?
Video A population has a mean of 200 and a standard deviation of 80 . Suppose a sample of size 100 is selected and is used to estimate μ. Use z-table. a. What is the probability that the sample mean will be within +9 of the population mean (to 4 decimals)? (Round z value in intermediate calculations to 2 decimal places.) b. What is the probablity that the sample mean will be within 13 of the population mean (to 4...