13. Scores on a national mathematics exam (The RVCMT) vary normally with a mean of 150...
13. Scores on a national mathematics exam (The RVCMT) vary normally with a mean of 150 points and a standard deviation of 30 points. a. What percentage of students taking the exam score at least 190? b. What is the 80 percentile of the exam? c. Based on an SRS of 25 students, what is the sampling distribution of the sample mean? Why? d. What is the probability that the mean score for an SRS of 25 students is less...
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?
Scores on the SAT mathematics section have a normal distribution with mean 4-500 and standard deviation o=100. a. What proportion of students score above a 550 on the SAT mathematics section? Round your answer to 4 decimal places. b. Suppose that you choose a simple random sample of 16 students who took the SAT mathematics section and find the sample mean x of their scores. Which of the following best describes what you would expect? The sample mean will be...
11. Scores on a national exam are normally distributed with mean 382 and standard deviation 26. Find the score that is the 50th percentile. b. Find the score that is the 90th percentile. a.
Problem 3: Scores on an exam are assumed to be normally distributed with mean /u = 75 and variance a2 = 25 (1) What is the probability that a person taking the examination scores higher than 70? (2) Suppose that students scoring in the top 10.03% of this distribution are to receive an A grade. What is the minimum score a student must achieve to earn an A grade? (3) What must be the cutoff point for passing the examination...
Scores on a recent national statistics exam were normally distributed with a mean of 72 and a standard deviation of 10 . What is the probability that a randomly selected exam will have a score between 75 and 80 ?
Scores on a recent national statistics exam were normally distributed with a mean of 88 and a standard deviation of 2. 1. What is the probability that a randomly selected exam will have a score of at least 85? 2. What percentage of exams will have scores between 89 and 92? 3. If the top 5% of test scores receive merit awards, what is the lowest score eligible for an award? I do not understand how to compute probability.
Suppose the scores on a statistic exam are normally distributed with a mean of 77 and a variance of 25. What is the 25th percentile of the scores? What is the percentile of someone who got a score of 62? What proportion of the scores are between 80 and 90? Suppose you select 35 tests at random, what is the proportion of scores above 85?
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) >...
The scores of students on an exam are normally distributed with a mean of 225 and a standard deviation of 38. (a) What is the lower quartile score for this exam? (Recall that the first quartile is the value in a data set with 25% of the observations being lower.)