Suppose that the distribution of marks on an exam is closely described by a normal curve...
Suppose that the distribution of marks on an exam is closely
described by a normal curve with a mean of 65. The 84th percentile
of this distribution is 75.
(a) What is the 16th percentile?
(b) What is the approximate value of the standard deviation
of
exam marks?
(c) What z-score is associated with an exam mark of 50?
(d) What percentile corresponds to an exam mark of 85?
(e) Do you think there were many marks below 35? Explain.
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Suppose that the distribution of marks on an exam is closely
described by a normal curve...
Suppose that the distribution of marks on an exam is closely described by a normal curve...
Suppose that the distribution of marks on an exam is closely described by a normal curve with a mean of 65. The 84th percentile of this distribution is 75. (a) What is the 16th percentile? (b) What is the approximate value of the standard deviation of exam marks? (c) What z-score is associated with an exam mark of 50? (d) What percentile corresponds to an exam mark of 85? (e) Do you think there were many marks below 35? Explain.
Lee's first history exam score is +2 standard deviations from the mean in a normal distribution....
Lee's first history exam score is +2 standard deviations from the mean in a normal distribution. The test has a mean of 65 and a standard deviation of 5. Lee's percentile rank would be approximately _____. a.97.5% b.65 % c.75 % d.none of the above
Consider a normal distribution curve where 85-th percentile is at 15 and the 35-th percentile is...
Consider a normal distribution curve where 85-th percentile is at 15 and the 35-th percentile is at 7. Use this information to find the mean, μ , and the standard deviation, σ , of the distribution.
18. Suppose the random variable x is best described by a normal distribution with u =...
18. Suppose the random variable x is best described by a normal distribution with u = 30 and o = 7.9. Find the Z-score that corresponds to each of the following x values. a. X=36, z= b. X=35, z=_ c. X=22, ze d. X=30, ZE e. X=19, ZF f. X=36, z
scores on an exam required for all medical school applicants were approximately normal with a mean...
scores on an exam required for all medical school applicants were approximately normal with a mean of 420 and a standard deviation of 8.2. a.) suppose an applicant had a test score of 520. what percentile corresponds with this score? b.) suppose to be considered at a highly selective school and applicant need to score the top 10%. what score would place the applicant on top of 10%
Suppose a random variable x is best described by a normal distribution with = 60 and...
Suppose a random variable x is best described by a normal distribution with = 60 and sigma=16. Find the z-score that corresponds to the value x = 0. 0 -3.75 0-16 O 16 0 3.75
For statistics expert The data in the table are simulated exam scores. Suppose the exam was...
For statistics expert
The data in the table are simulated exam scores. Suppose the exam was given in the semester after the course content was revised, and the previous mean exam score was 70. We would like to know whether or not the mean score has increased. Answer the following question using any approximate method by stating the necessary assumptions. The data are here: Simulated Exam Scores 75 70 88 80 80 66 65 68 85 80 78 72 69...
Suppose that, for a certain exam, a teacher grades on a curve. It is known that...
Suppose that, for a certain exam, a teacher grades on a curve. It is known that the mean is 65 and the standard deviation is 10. There are 30 students in the class. What score would be necessary to obtain an A?
Suppose a newspaper article states that the distribution of auto insurance premiums for residents of California...
Suppose a newspaper article states that the distribution of auto insurance premiums for residents of California is approximately normal with a mean of 1633. The article also states that 15% of California residents pay more than 1950. 1. What is the Z score that corresponds to the top 15% (or the 85thth percentile) of the standard normal distribution? Round your answer to 4 decimal places. 2. What is the mean insurance cost? 3. What is the cutoff for the 85thth...
The distribution of scores on a recent test closely followed a Normal Distribution with a mean...
The distribution of scores on a recent test closely followed a Normal Distribution with a mean of 22 points and a standard deviation of 2 points. For this question, DO NOT apply the standard deviation rule. (a) What proportion of the students scored at least 26 points on this test, rounded to five decimal places? (b) What is the 42 percentile of the distribution of test scores, rounded to three decimal places?
18. Suppose the random variable x is best described by a normal distribution with u = 30 and o = 7.9. Find the Z-score that corresponds to each of the following x values. a. X=36, z= b. X=35, z=_ c. X=22, ze d. X=30, ZE e. X=19, ZF f. X=36, z
Suppose a random variable x is best described by a normal distribution with = 60 and sigma=16. Find the z-score that corresponds to the value x = 0. 0 -3.75 0-16 O 16 0 3.75
For statistics expert
The data in the table are simulated exam scores. Suppose the exam was given in the semester after the course content was revised, and the previous mean exam score was 70. We would like to know whether or not the mean score has increased. Answer the following question using any approximate method by stating the necessary assumptions. The data are here: Simulated Exam Scores 75 70 88 80 80 66 65 68 85 80 78 72 69...
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