Question

The eighth-grade students at a large school district took a standardized math exam. Suppose that the...

The eighth-grade students at a large school district took a standardized math exam. Suppose that the scores were normally distributed with mean 77 and standard deviation 12. A sample of 30 scores is randomly selected.

(a)

Find the mean of the sampling distribution of the mean scores from samples of size 30.

μx =

(b)

Find the standard deviation of the sampling distribution from part (a). (Round your answer to three decimal places.)

σx =

Math   Statistics-And-Probability   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

Solution :

Given that ,

mean = = 77

standard deviation = = 12

n = 30

(a)

sampling distribution of the mean   =

(b

standard deviation of the sampling distribution

=  / n = 12/ 30=2.191

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
In a school district, all sixth grade students take the same standardized test. The superintendant of...
In a school district, all sixth grade students take the same standardized test. The superintendant of the school district takes a random sample of 23 scores from all of the students who took the test. She sees that the mean score is 147 with a standard deviation of 18.9631. The superintendant wants to know if the standard deviation has changed this year. Previously, the population standard deviation was 12. Is there evidence that the standard deviation of test scores has...
In a school district, all sixth grade students take the same standardized test. The superintendant of...
In a school district, all sixth grade students take the same standardized test. The superintendant of the school district takes a random sample of 26 scores from all of the students who took the test. She sees that the mean score is 121 with a standard deviation of 14.3688. The superintendant wants to know if the standard deviation has changed this year. Previously, the population standard deviation was 24. Is there evidence that the standard deviation of test scores has...
26. The scores on a standardized math test for 8th grade children form a normal distribution...
26. The scores on a standardized math test for 8th grade children form a normal distribution with a mean of 80 and a standard deviation of 10. (8 points) a. What proportion of the students have scores less than X = 83? b. If samples of n = 6 are selected from the population, what proportion of the samples have means less than M = 83? c. If samples of n = 30 are selected from the population, what proportion...
3) A school administrator claims that the standard deviations of math assessment scores for 8th grade...
3) A school administrator claims that the standard deviations of math assessment scores for 8th grade students are the same in Districts 3 and 4. A random sample of 12 scores in District 3 had a standard deviation of 36.8 points and a random sample of 14 scores in District 4 had a standard deviation of 32.5 points. At ? = 0.10, what can be said about the administrator’s claim? Assume the populations are normally distributed and complete all seven...
In a recent​ year, scores on a standardized test for high school students with a 3.50...
In a recent​ year, scores on a standardized test for high school students with a 3.50 to 4.00 grade point average were normally​ distributed, with a mean of 38.238.2 and a standard deviation of 2.22.2. A student with a 3.50 to 4.00 grade point average who took the standardized test is randomly selected. ​(a) Find the probability that the​ student's test score is less than 3737. The probability of a student scoring less than 3737 is 0.29120.2912. ​(Round to four...
The National Assessment of Educational Progress (NAEP) includes a mathematical test for eighth?grade students. Scores on...
The National Assessment of Educational Progress (NAEP) includes a mathematical test for eighth?grade students. Scores on the test range from 0 to 500 . Suppose that you give the NAEP test to an SRS of 1000 eighth?graders from a large population in which the scores have mean 299 and standard deviation 116 . The mean x ¯ will vary if you take repeated samples. The sampling distribution of x ¯ is approximately Normal. It has mean 299 . What is...
If a school district takes a random sample of 81 Math SAT scores and finds that...
If a school district takes a random sample of 81 Math SAT scores and finds that the average is 486, and knowing that the population standard deviation of Math SAT scores is intended to be 100. Find a 99% confidence interval for the mean math SAT score for this district. ? ≤ μ≤ ≤ If a school district takes a random sample of 81 Math SAT scores and finds that the average is 486, and knowing that the population standard...
A random sample of 81 eighth grade students' scores on a national mathematics assessment test has...
A random sample of 81 eighth grade students' scores on a national mathematics assessment test has a mean score of 288. This test result prompts a state school administrator to declare that the mean score for the state's eighth graders on this exam is more than 280. Assume that the population standard deviation is 34. At alpha=0.06, is there enough evidence to support the administrator's claim? (a) Write the claim mathematically and identify Upper H 0and Upper H Subscript a...
A math professor notices that scores from a recent exam are Normally distributed with a mean...
A math professor notices that scores from a recent exam are Normally distributed with a mean of 65 and a standard deviation of 9. (a) What score do 25% of the students exam scores fall below? (b) Suppose the professor decides to grade on a curve. If the professor wants 16% of the students to get an A, what is the minimum score for an A?
A math professor notices that scores from a recent exam are normally distributed with a mean...
A math professor notices that scores from a recent exam are normally distributed with a mean of 72 and a standard deviation of 5. (a) What score do 75% of the students exam scores fall below? Answer: (b) Suppose the professor decides to grade on a curve. If the professor wants 2.5% of the students to get an A, what is the minimum score for an A? Answer:
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT