Determining the normal distribution

Reference no: EM13985504

The following data give SAT mean scores for math by state for 1989 and 1999 for 20 randomly selected states (source: The World Almanac and Book of Facts 2000).

State	1989	1999
Arizona	523	525
Connecticut	498	509
Alabama	539	555
Indiana	487	498
Kansas	561	576
Oregon	509	525
Nebraska	560	571
New York	496	502
Virginia	507	499
Washington	515	526
Illinois	539	585
North Carolina	469	493
Georgia	475	482
Nevada	512	517
Ohio	520	568
New Hampshire	510	518

Assuming that the samples come from a normal distribution:

(a) Test that the mean SAT score for math in 1999 is greater than that in 1989 at α = 0.05. Assume the variances are equal.

(b) Test for the equality of the variances at α = 0.05.

Reference no: EM13985504

Questions Cloud

Probability that the number of cars arriving : Find, using Chebyshev's inequality, a lower bound for the probability that the number of cars arriving at the intersection in 1 hour is between 70 and 130.

Variable with probability density function : Let X be a random variable with probability density function 630x4(1 - x)4, 0 1,f(x) = 0, otherwise.

Test the hypothesis that choice of major : Test the hypothesis that the choice of the major by undergraduate students in this university is independent of their gender. Use α = 0.01.

Opinion on collective bargaining by teachers : The following table gives the opinion on collective bargaining by a random sample of 200 employees of a school system, belonging to a teachers' union.

Determining the normal distribution : Assuming that the samples come from a normal distribution: Test that the mean SAT score for math in 1999 is greater than that in 1989 at α = 0.05. Assume the variances are equal.

What is the total liquid and vapor flow rates : Determine whether this processes is a stripping process or an absorption process and what is the total liquid and vapor flow rates at the entrance and exit of the tower?

Problem regarding the equality of variances between the iqs : The IQs of 17 students from one area of a city showed a mean of 106 with a standard deviation of 10, whereas the IQs of 14 students from another area showed a mean of 109 with a standard deviation of 7.

Difference between the two population means : At the conclusion of the instructional period, a reading test gave results y1 = 74, y2 = 71, s1 = 9, and s2 = 10. What is the attained signi?cance level if you wish to see if there is evidence of a real difference between the two population means?..

Problem regarding the sample standard deviation : A random sample of 40 of these batteries was tested, resulting in a sample mean life of 41 months with a sample standard deviation of 16 months. Test at α = 0.01 whether the manufacturer's claim is correct.

User Account

All Pages