Scores for men on the verbal portion of the SAT-I test are normally distributed with a mean of 509 and a standard deviation of 108. A random sample of 36 men is selected.
To plan for the Betropolis High School Faculty Picnic a group consisting of two women and two men will be formed. If there are 10 women, 7 men who have volunteered then in how many different ways can the group be formed?
A study is designed to find the mean weight of a fish caught by a fishing company. Find the minimum sample size needed in order to construct a 95% confidence interval for the mean weight of such salmon, to within 0.20 pounds. Assume that the standard deviation=2.10
Polls showed the two main candidates in the 2004 presidential election were nearly tied on the day before the election. To predict the winner a newspaper would like to have a poll that has a margin of error of less than 1%. Roughly how large a sample would be needed for such a poll?
If x is a binomial random variable, calculate μ ,σ2 ,and σ for each of the following values of n and p. Complete parts a through f.a. n=25 ,p=0.5
(a) Use Excel to sketch a graph of the standard normal distribution with a mean of 0 and a standard deviation of 1. Generate x values in column A ranging from -3 to 3 in increments of 0.5. Use NORM.DIST to generate the y values in column B. (b) Use Excel to sketch a graph […]
Managers at an automobile manufacturing plant would like to estimate the mean completion time of an assembly line operation, m. The managers plan to choose a random sample of completion times and estimate m via the sample. Assuming that the standard deviation of the population of completion times is 10.1 minutes, what is the minimum […]
7. The expected frequency of a category is given by Ε = np where n is the sample size and p is the probability that an element belongs to that category if the null hypothesis is true. The ________ for a goodness–of–fit test are k – 1, where k denotes the number of possible outcomes (or […]
The media selection manager for an advertising agency inserts the same advertisement for a client bank in two magazines, similarly placed in each. One month later, a market research study finds that 226 of 473 readers of the first magazine are aware of the banking services offered in the ad, as are 165 of 439 […]
In developing patient appointment schedules, a medical center desires an estimate of the mean time that a staff member spends with each patient. How large a sample should be taken if the precision of the estimate is to be +/- 3 minutes at an 85% level of confidence? Use a planning value for the population […]