Grades on a standardized test are known to have a mean of 940 for students in...

a) The 95% confidence interval for the average test score for Florida students is ( 942.67, 961.77). (Round your responses to two decimal places.)

b) Is there statistically significant evidence that Florida students perform differently than other students in the United States?

The 95% confidence interval for the average test score for Florida students does not include mu = 940, so the null hypothesis that mu = 940 (that Florida students have the same average performance as other students in the United States) can be rejected at the 5% level.

c) Another 486 students are selected at random from Florida. They are given a 3-hour preparation course before the test is administered. Their average test score is 957.86 with a standard deviation of 89.30. The 95% confidence interval for the change in average test score associated with the prep course is ( nothing, nothing). (Round your responses to two decimal places.)

Solutions

Expert Solution

orchestra answered 1 year ago

Next > < Previous

Related Solutions

Grades on a standardized test are known to have a mean of 940 for students in...

Grades on a standardized test are known to have a mean of 940 for students in the United States. The test is administered to 436 randomly selected students in Florida; in this sample, the mean is 952.22 and the standard deviation (s) is 101.52. The 95% confidence interval for the average test score for Florida students is (__ , __). (Round your responses to two decimal places.)

Grades on a standardized test are known to have a mean of 10901090 for students in...

Grades on a standardized test are known to have a mean of 10901090 for students in the United States. The test is administered to 458458 randomly selected students in Florida; in this sample, the mean is 1104.171104.17 and the standard deviation (s) is 117.72117.72. Another 508508 students are selected at random from Florida. They are given a 3-hour preparation course before the test is administered. Their average test score is 1110.711110.71 with a standard deviation of 103.55103.55. The 95% confidence...

) Grades on a standardized test are known to have a mean of 1000 for students...

) Grades on a standardized test are known to have a mean of 1000 for students in the US. The test is administered to 453 randomly selected students from Queens College, and they obtained an average grade of 1013 and a standard deviation of 108. a. Construct a 95 % confidence interval for the true average test score for Queens College students.(1pt) b. With 5% significance level, Is there a statistical evidence that Queens College students perform differently than other...

Grades on a standardized test are known to have a mean of 500 for students in...

Grades on a standardized test are known to have a mean of 500 for students in the US. The test is administered to 600 randomly selected students in Florida. In this subsample, the mean is 508, and the standard deviation is 75 i. Construct a 95% confidence interval for the average test score for students in Florida. ii. Is there statistically significant evidence that students in Florida perform differently from other students in the US? iii. Another 500 students are...

On a statistics test for a class of 40 students, the grades were normally distributed.The mean...

On a statistics test for a class of 40 students, the grades were normally distributed.The mean grade was 74, and the standard deviation was 8. 2. Janis scored 76 on this test. A. What was her z-score for this grade b. What percent of the class scored lower than Janis? c. Approximately how many students in the class scored lower than Janis? 3. The minumum passing grade on this test was 70. Approximately how many students scored lower than 70...

A large group of students took a test in physics and the final grades have a...

A large group of students took a test in physics and the final grades have a mean of 70 and a standard deviation of 10. If we can approximate the distribution of theses grades by a normal distribution, what percent of students a. Score higher than an 80 but less than 90? b. Should pass the test (grades > 60)? c. Should fail the test (grades < 60)? d. If you randomly sample 30 students, what is the probability that...

A large group of students took a test in Statistics and the final grades have a...

A large group of students took a test in Statistics and the final grades have a mean of 70 and a standard deviation of 10. If we can approximate the distribution of these grades by a normal distribution, what percent of the students a) scored between 50 and 90? b) scored higher than 90? c) should pass the test (grades≥50) d)non of the above d) should fail the test (grades<50)?

6) A standardized reading achievement test for 5th grade students has a nationwide mean of μ...

6) A standardized reading achievement test for 5th grade students has a nationwide mean of μ = 70. A teacher would like to know whether the students in her fifth grade class are significantly different from the national average. The test is given to the entire class of n = 25 students and the average score is 75 with SS = 2400. a) Using a two-tailed test with α = .05, is this class significantly different from the national...

A teacher looks at the scores on a standardized test, where the mean of the test...

A teacher looks at the scores on a standardized test, where the mean of the test was a 73 and the standard deviation was 9. Find the following z-score table Link What is the probability that a student will score between 73 and 90 What is the probability that a student will score between 65 and 85 What is the probability that a student will get a score greater than 70 What is the probability that a student will score...

A psychological test was standardized for a population of tenth-grade students in such a way that...

A psychological test was standardized for a population of tenth-grade students in such a way that the mean must be 500 and the standard deviation must be 100. A sample of 90 twelfth-grade students was selected independently and at random, and each given the test. The sample mean turned out to be 506.7. On this basis, can one say that the population distribution for twelfth grade students would differ from that of tenth-graders?

Subjects