Question

In: Statistics and Probability

A standardized college admissions test has a population mean of 65, a population standard deviation of...

  1. A standardized college admissions test has a population mean of 65, a population standard deviation of 10 points, and is normally distributed. If a student scores a 73 on the test, above what percentage of the test-takers does her score fall? Be sure to show your calculations.

Solutions

Expert Solution

Ans. We have given the information for population mean , also the population standard deviation and the population is normally distributed. So now if a we randomly select a student with the score of then we need to find the percentage of population of students who has the score below .

The formula for to calculate the Z-score is:

So, the Z-score is calculated as

Now, we have to find the percentage of population below this Z-score-

In other words, the percentage of population below the student whose score is is 78.81%.

We also say that the student who score is fall above 78.81% of population.


Related Solutions

Scores for a common standardized college aptitude test are normally distributed with a mean of 515 and a standard deviation of 113.
Scores for a common standardized college aptitude test are normally distributed with a mean of 515 and a standard deviation of 113. Randomly selected men are given a Test Prepartion Course before taking this test. Assume, for sake of argument, that the test has no effect.A. If 1 of the men is randomly selected, find the probability that his score is at least 584.2.P(X > 584.2) =  Round to 4 decimal places.NOTE: Answers obtained using exact z-scores or z-scores rounded to...
normal population has a mean of 65 and a standard deviation of 13. You select a...
normal population has a mean of 65 and a standard deviation of 13. You select a random sample of 16. Compute the probability that the sample mean is: (Round your z values to 2 decimal places and final answers to 4 decimal places): Greater than 67. Less than 64. Between 64 and 67.
A normally distributed population has a mean of 65 and a standard deviation of 24. Sample...
A normally distributed population has a mean of 65 and a standard deviation of 24. Sample averages from samples of size 19 are collected. What would be the lower end of the centered interval that contains 90% of all possible sample averages? I know how to do a most of this, but I am confused on how I find the Z variable. Thanks!
Consider a population of 300 with a mean of 65 and a standard deviation equal to...
Consider a population of 300 with a mean of 65 and a standard deviation equal to 25. What is the probability of obtaining a sample mean of 67 or less from a sample of 40? cumulative standardized normal table round to four decimal points
The SAT is a standardized college admissions test used in the United States. The following two...
The SAT is a standardized college admissions test used in the United States. The following two multi-part questions will ask you some questions about SAT testing. This is a 6-part question asking you to determine some probabilities of what happens when a student guessed for all of their answers on the SAT. Use the information below to inform your answers for the following questions. An old version of the SAT college had a -0.25 point penalty for every incorrect answer...
1. A test of reading ability has a population mean of 75 and a standard deviation...
1. A test of reading ability has a population mean of 75 and a standard deviation of 10 when given to third-graders. The distribution is known to be approximately normally distributed. a. What is the probability that a student will score above a 90? Show your calculation. b. What test score corresponds to the 25th percentile? Show your calculation. Say that you selected a random sample of 40 third-grade students from this population. c. What is the probability that the...
In a large population of college-educated adults, the mean IQ is 118 with a standard deviation...
In a large population of college-educated adults, the mean IQ is 118 with a standard deviation of 20. Suppose 200 adults from this population are randomly selected for a market research campaign. The probability that the sample mean IQ is greater than 120 is Select one: a. 0.0001. b. 0.0790. c. 0.1230. d. 0.9210. e. Cannot be determined
Given a standardized a normal distribution (with a mean of 0 and a standard deviation of...
Given a standardized a normal distribution (with a mean of 0 and a standard deviation of 1, as in Table E.2), what is that probability that a. Z is less than 1.57? b. Z is greater than 1.84? c. Z is between 1.57 and 1.84? d. Z is less than 1.57 or greater than 1.84?
A certain IQ test is known to have a population mean of 100 and standard deviation...
A certain IQ test is known to have a population mean of 100 and standard deviation of 15 in the general population. You want to test whether psychology majors have a different average IQ than the population as a whole. Assume the variance of IQ is the same for Psych majors as it is in the general population. Suppose that Psychology majors actually have an average IQ of 108. If you do a 2-tailed test at α= .05 with a...
In a large population of college-educated adults, the mean IQ is 112 with standard deviation 25....
In a large population of college-educated adults, the mean IQ is 112 with standard deviation 25. Suppose 100 adults from this population are randomly selected for a market research campaign. What is the probability that the sample mean IQ is lower than 105?
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT