Concept explainers
A recent study of 100 social workers in a southern state found that their
Sample1: Social workers in a southern state, Sample2: Social workers in awestern state.
a) Find the test statistic
b) Find critical value
a). Sample1-
sample size=
sample mean=$23000=
population mean=
Sample2-
sample size=
sample mean==$34200
population mean=
hypotheses to be tested here will be,
So, the test statistic will be given by,
where
Therefore, s=2692.486
Value of t under null hypothesis is -29.029
So,
Trending nowThis is a popular solution!
Step by stepSolved in 2 steps
- The results of a common standardized test used in physchology research is designed so that the population mean is 155 and the standard deviation is 30. A subject earns a score of 98. What is the z-score for this raw score?arrow_forwardA student takes a test in his math course and scores 45 points and a test in his psychology courseand scores 71 points. Scores on each test were normally distributed. On the math test the classhas a mean of 40 and a standard deviation of 15. On the psychology test the class has a mean of 75and a standard deviation of 10. On which test did the student do better?arrow_forwardThe U.S. Department of Agriculture claims that the mean consumption of bottled water by a person in the United States is 28.5 gallons per year. A random sample of 100 people in the United States had a mean bottled water consumption of 27.8 gallons per year with a standard deviation of 4.1 gallons. Does this sample indicate that the mean annual consumption of bottled water for people in the United States is not 28.5 gallons per year? (Reference: U.S. Department of Agriculture) At a 5% level of significance, what is the power of this test against the alternative μ= 27.4? (For this problem only, assume that the standard deviation of the population (i.e. sigma) is 4.1) O 77% 5% 85% 0.90%arrow_forward
- It has been found that with the standard dosage of a drug, the change in people’s uric acid levelis normally distributed with a mean of 240 and a standard deviation of 60. What proportionof people receiving the standard dosage of this drug experience changes in uric acid levelbetween 210 and 270?arrow_forwardThe speed of cars driving past Johnson City High School, on 666 Reynolds Rd, were recorded over one school year. The speed limit on that part of Reynolds Rd is 20 mph. The mean of the speed readings was 24.19 mph, with a standard deviation of 3.56 mph.arrow_forwardThe results of a common standardized test used in psychology research is designed so that the population mean is 175 and the standard deviation is 10. A subject earns a score of 183. What is the z-score for this raw score?arrow_forward
- A survey reported that in a recent year, the mean serum cholesterol level in milligrams per deciliter for US adults was 204 with a standard deviation of 37. A random sample of 116 adults was chosen. Find the 33rd percentile of the sample mean.arrow_forwardA successful basketball player has a height of 6 feet 11 inches, or 211 cm. Based on statistics from a data set, his height converts to the z score of 5.17. How many standard deviations is his height above the mean?arrow_forwardIf the weight of fertilizer in a 40-pound bag is normally distributed with a standard deviation of 0.5 pounds, what is the range of weights of bags of fertilizer within two standard deviations of the mean?arrow_forward
- A recent study found that 61 children who watched a commercial for potato chips featuring a celebrity endorser ate a mean of 39 grams of potato chips as compared to a mean of 28 grams for 51 children who watched a commercial for an alternative food snack. Suppose that the sample standard deviation for the children who watched the celebrity-endorsed commercial was 21.2 grams and the sample standard deviation for the children who watched the alternative food snack commercial was 12.7 grams. What is the test statistic? tSTAT= __________ (Round to two decimal places as needed.)arrow_forwardA pupil in grade 2 jumped 3.2 m for the long jump. The class mean is 2.5 m with a standard deviation of 0.4 m. A pupil in grade 8 at the same school jumped 4.3 m in a class with a mean of 3.4 m and a standard deviation of 0.5 m. Which student should receive the long jump medal for the school track meet?arrow_forward
- MATLAB: An Introduction with ApplicationsStatisticsISBN:9781119256830Author:Amos GilatPublisher:John Wiley & Sons IncProbability and Statistics for Engineering and th...StatisticsISBN:9781305251809Author:Jay L. DevorePublisher:Cengage LearningStatistics for The Behavioral Sciences (MindTap C...StatisticsISBN:9781305504912Author:Frederick J Gravetter, Larry B. WallnauPublisher:Cengage Learning
- Elementary Statistics: Picturing the World (7th E...StatisticsISBN:9780134683416Author:Ron Larson, Betsy FarberPublisher:PEARSONThe Basic Practice of StatisticsStatisticsISBN:9781319042578Author:David S. Moore, William I. Notz, Michael A. FlignerPublisher:W. H. FreemanIntroduction to the Practice of StatisticsStatisticsISBN:9781319013387Author:David S. Moore, George P. McCabe, Bruce A. CraigPublisher:W. H. Freeman