STATISTICS FINAL COMPREHENSIVE
EXAM SOLVED QUESTIONS GRADED A+
◉ Directions: Use the fact that the population of I.Q. scores are
normally distributed with a mean of 100 and a standard deviation
of 15 to answer the following questions. Please show all of the
steps in each solution.
2. Find the probability that a randomly selected person has an IQ
of greater than 130.
[ i.e. P(x > 130) ]
Answer: 0.0228
◉ Directions: Use the fact that the population of I.Q. scores are
normally distributed with a mean of 100 and a standard deviation
of 15 to answer the following questions. Please show all of the
steps in each solution.
3. Find the probability that a randomly selected person has an I.Q.
below 118.
Answer: 0.8849
◉ Directions: Show a complete solution to the following
problems. Please include your normal curve drawings with the
appropriate z-scores and shading.
The average waiting time for a drive-in window at a local bank is
normally distributed with a mean of 9.2 minutes and a standard
, deviation of 2.6 minutes. Find the probability that a person
chosen at random will have to wait
1. between 6 to 12 minutes
Answer: 0.7506
◉ Directions: Show a complete solution to the following
problems. Please include your normal curve drawings with the
appropriate z-scores and shading.
The average waiting time for a drive-in window at a local bank is
normally distributed with a mean of 9.2 minutes and a standard
deviation of 2.6 minutes. Find the probability that a person
chosen at random will have to wait
1. less than 5 minutes
Answer: 0.0526
◉ Find the cut-off scores for each problem below using the
Reverse Normal Equation. Draw an appropriate normal curve
diagram for each example when finding the z-score.
Assume that IQ scores are normally distributed with μ=100 and
σ=15. Find the 90th percentile for IQ scores.
Answer: 119.2
EXAM SOLVED QUESTIONS GRADED A+
◉ Directions: Use the fact that the population of I.Q. scores are
normally distributed with a mean of 100 and a standard deviation
of 15 to answer the following questions. Please show all of the
steps in each solution.
2. Find the probability that a randomly selected person has an IQ
of greater than 130.
[ i.e. P(x > 130) ]
Answer: 0.0228
◉ Directions: Use the fact that the population of I.Q. scores are
normally distributed with a mean of 100 and a standard deviation
of 15 to answer the following questions. Please show all of the
steps in each solution.
3. Find the probability that a randomly selected person has an I.Q.
below 118.
Answer: 0.8849
◉ Directions: Show a complete solution to the following
problems. Please include your normal curve drawings with the
appropriate z-scores and shading.
The average waiting time for a drive-in window at a local bank is
normally distributed with a mean of 9.2 minutes and a standard
, deviation of 2.6 minutes. Find the probability that a person
chosen at random will have to wait
1. between 6 to 12 minutes
Answer: 0.7506
◉ Directions: Show a complete solution to the following
problems. Please include your normal curve drawings with the
appropriate z-scores and shading.
The average waiting time for a drive-in window at a local bank is
normally distributed with a mean of 9.2 minutes and a standard
deviation of 2.6 minutes. Find the probability that a person
chosen at random will have to wait
1. less than 5 minutes
Answer: 0.0526
◉ Find the cut-off scores for each problem below using the
Reverse Normal Equation. Draw an appropriate normal curve
diagram for each example when finding the z-score.
Assume that IQ scores are normally distributed with μ=100 and
σ=15. Find the 90th percentile for IQ scores.
Answer: 119.2
