A personnel director in a particular state claims that the mean annual income is greater in one of the state's counties (county A) than it is in another county (county B). In County A, a random sample of 12 residents has a mean annual income $40,800 and a standard deviation of $8800. In County B, a random sample of 10 residents has a mean annual income of $40,000 and a standard deviation of $5800. At a = 0.005, answer parts (a) through (e). Assume the population variances are not equal. If convenient, use technology to solve the problem. a) Identify the claim and state H, and H. Which is the correct claim below? A. "The mean annual income in county A is greater than in county B." OB. "The mean annual income in county A is less than in county B." O C. "The mean annual incomes counties A and B are not equal." O D. "The mean annual incomes counties A and B are equal." What are Ho and H,? The null hypothesis, Ho, is H, s H2 . The alternative hypothesis, H, is u, >2 ·. Which hypothesis is the claim? * The alternative hypothesis, H O The null hypothesis, Ho b) Find the critical value(s) and identify the rejection region(s). Enter the critical value(s) below. Type an integer or decimal rounded to three decimal places as needed. Use a comma to separate answers as needed.)
Inverse Normal Distribution
The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.
Mean, Median, Mode
It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.
Z-Scores
A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.
Trending now
This is a popular solution!
Step by step
Solved in 2 steps