QUESTION 20 The mean score on a standardized exam is 320 with a standard deviation of 40. Suppose 100 scores are randomly selected and you need to determine the probability that the sample mean is less than 310. Calculate the z-score necessary to do this
0.25
2.50
-2.50
-0.25
QUESTION 20 The mean score on a standardized exam is 320 with a standard deviation of...
8. Suppose the scores of students on an exam are normally distributed with mean u = 17.6 and standard deviation o = 4.9. (a) Determine the distribution of the sample mean score for a randomly selected sample of 36 students who took the exam. (b) Find the probability that the sample mean score will be less than 20 for a sample of 36 randomly selected students. (c) How large a sample size would be required to ensure that the probability...
Students taking a standardized IQ test had a mean score of 98 with a standard deviation of 12. If a random sample of 36 students is selected, find the probability that their mean score is less than 94. Leave your answer as a decimal with 4 decimal places.
7. Scores on a recent national Mathematics exam were normally distributed with a mean of 82 and a standard deviation of 7. A. What is the probability that a randomly selected exam score is less than 70 B. What is the probability that a randomly selected exam score is greater than 90? C. If the top 2.5% of test scores receive Merit awards, what is the lowest score necessary to receive a merit award?
In a recent year, the total scores for a certain standardized test were normally distributed, with a mean of 500 and a standard deviation of 10.5. Answer parts (a)-(d) below. (a) Find the probability that a randomly selected medical student who took the test had a total score that was less than 490. (Round to four decimal places as needed.) The probability that a randomly selected medical student who took the test had a total score that was less than 490 is 0.1704 (b)...
In a recent year, the total scores for a certain standardized test were normally distributed, with a mean of 500 and a standard deviation of 10.4. Find the probability that a randomly selected medical student who took the test had a total score that was more than 530. The probability that a randomly selected medical student who took the test had a total score that was more than 530 is _______
In a recent year, the total scores for a certain standardized test were normally distributed, with a mean of 500 and a standard deviation of 10.6. Find the probability that a randomly selected medical student who took the test had a total score that was more than 529. The probability that a randomly selected medical student who took the test had a total score that was more than 529 is _______
Question 1 The average math SAT score is 511with a standard deviation of 119. A particular high school claims that its students have unusually high math SAT scores. A random sample of 50 students from this school was selected, and the mean math SAT score was 555. Is the high school justified in its claim? Explain. ▼ Pick one No Yes because the z-score (what is the z score) (?) is ▼ pick one not unusual unusual since it ▼...
7. z-scores and standardized scores Is a z-score a standardized score? No Yes Consider the following distribution of scores with a mean of 50 and a standard deviation of 10. For the letters A, B, C, and D in the boxes beneath the ine labeled "z" give the z-scores corresponding to each position in the distribution. One z-score is already filled in (-1) Suppose you also want to standardize these scores to a "k" scale where the mean of k...
The scores on a Statistics exam are normally distributed with a mean 75 with a standard deviation of 5. If nine students are randomly selected what is the probability that their mean score is greater than 68. (a) .0808 (b) -.4000 (c) .9192 (d) .0001 (e) .9999 29. Refer to question 28. Suppose that students with the lowest 10% of scores are placed on academic probation, what is the cutoff score to avoid being placed on academic probation? (a) >...
A final exam in MTH 160 has a mean of 73.0 with standard deviation 7.8. If 45 students are randomly selected from MTH 160, find the probability that the mean of their test scores is less than 76. 0.9951 0.3503 0.6497 0.0049