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Personnel dexterity tests. Personnel tests are designed to
Chapter 4, Problem 109E(choose chapter or problem)
Personnel dexterity tests. Personnel tests are designed to test a job applicant’s cognitive and/or physical abilities. The Wonderlic IQ test is an example of the former; the Purdue Pegboard speed test involving the arrangement of pegs on a peg board is an example of the latter. A particular dexterity test is administered nationwide by a private testing service. It is known that for all tests administered last year, the distribution of scores was approximately normal with mean 75 and standard deviation 7.5.
a. A particular employer requires job candidates to score at least 80 on the dexterity test. Approximately what percentage of the test scores during the past year exceeded 80?
b. The testing service reported to a particular employer that one of its job candidate’s scores fell at the 98th percentile of the distribution (i.e., approximately 98% of the scores were lower than the candidate’s, and only 2% were higher). What was the candidate’s score?
Questions & Answers
QUESTION:
Personnel dexterity tests. Personnel tests are designed to test a job applicant’s cognitive and/or physical abilities. The Wonderlic IQ test is an example of the former; the Purdue Pegboard speed test involving the arrangement of pegs on a peg board is an example of the latter. A particular dexterity test is administered nationwide by a private testing service. It is known that for all tests administered last year, the distribution of scores was approximately normal with mean 75 and standard deviation 7.5.
a. A particular employer requires job candidates to score at least 80 on the dexterity test. Approximately what percentage of the test scores during the past year exceeded 80?
b. The testing service reported to a particular employer that one of its job candidate’s scores fell at the 98th percentile of the distribution (i.e., approximately 98% of the scores were lower than the candidate’s, and only 2% were higher). What was the candidate’s score?
ANSWER:Step 1 of 2
The distribution of score was approximately normal with mean 75 and standard deviation 7.5.
Our goal is :
a). We need to find what percentage of the test scores during the past year exceeded 80.
b). We need to find the what was the candidate's score.
a). A particular employer require job candidates to score at least 80 on the dexterity test.
Now we have to find what percentage of the test scores during the past year exceeded 80.
The formula for the z score is
\(z=\frac{x-\mu}{\sigma}\)
We know that \(\mu\) and \(\sigma\).
Here x = 80.
Then,
\(\begin{array}{l}
z=\frac{80-75}{7.5} \\
z=\frac{5}{2.5} \\
z=0.67
\end{array}\)
Therefore, z = 0.67.
Then the probability of x is greater than 80 is
P(x > 80) = 1 - P(z < 0.67)
From area under the normal table.
P(x > 80) = 1 - 0.7486
P(x > 80) = 0.2514
Therefore, 25.14% of the scores exceeded 80.