Question

In: Math

The time needed to complete a final examination in a particular college course is normally distributed...

The time needed to complete a final examination in a particular college course is normally distributed with a mean of 100 minutes and a standard deviation of 20 minutes. Answer the following questions.

(a)What is the probability of completing the exam in one hour or less?

(b) What is the probability that a student will complete the exam in more than 60 minutes but less than 75 minutes?

(c) Assume that the class has 90 students and that the examination period is 130 minutes in length. How many students do you expect will be unable to complete the exam in the allotted time

Solutions

Expert Solution

Solution :

Given that ,

mean = = 100 minutes

standard deviation = = 20 minutes

a) P(x 60)

= P[(x - ) / (60 - 100) / 20]

= P(z -2)

Using z table,

= 0.0228

b) P(60 < x < 75) = P[(60 - 100) / 20) < (x - ) /  < (75 - 100) / 20) ]

= P(-2 < z < -1.25)

= P(z < -1.25) - P(z < -2)

Using z table,

= 0.1056 - 0.0228

= 0.0828

c) n = 90

P(x > 130) = 1 - p( x< 130)

=1- p P[(x - ) / < (130 - 100) / 20]

=1- P(z < 1.5)

Using z table,

= 1 - 0.9332

= 0.0668

= 0.0668 * 90 = 6 students


Related Solutions

The time needed to complete a final examination in a particular college course is normally distributed...
The time needed to complete a final examination in a particular college course is normally distributed with a mean of 83 minutes and a standard deviation of 13 minutes. Answer the following questions. a. What is the probability of completing the exam in one hour or less (to 4 decimals)? b. What is the probability that a student will complete the exam in more than 60 minutes but less than 75 minutes (to 4 decimals)? c. Assume that the class...
The time needed to complete a final examination in a particular college course is normally distributed...
The time needed to complete a final examination in a particular college course is normally distributed with a mean of 83 minutes and a standard deviation of 13 minutes. Answer the following questions. Round the intermediate calculations for z value to 2 decimal places. Use Table 1 in Appendix B. What is the probability of completing the exam in one hour or less (to 4 decimals)? What is the probability that a student will complete the exam in more than...
The time needed to complete a final examination in a particular college course is normally distributed...
The time needed to complete a final examination in a particular college course is normally distributed with a mean of 79 minutes and a standard deviation of 8 minutes. Answer the following questions. Round the intermediate calculations for z value to 2 decimal places. What is the probability of completing the exam in one hour or less (to 4 decimals)? What is the probability that a student will complete the exam in more than 60 minutes but less than 75...
The time needed to complete a final examination in a particular college course is normally distributed...
The time needed to complete a final examination in a particular college course is normally distributed with a mean of 100 minutes and a standard deviation of 20 minutes. Answer the following questions. (a) What is the probability of completing the exam in one hour or less? (b) What is the probability that a student will complete the exam in more than 60 minutes but less than 75 minutes? (c) Assume that the class has 90 students and that the...
1. The time need to complete a final examination in a college course is normally distributed...
1. The time need to complete a final examination in a college course is normally distributed with a mean of 80 minutes and a standard deviation of 10 minutes. a. What is the probability of completing the exam in less than 60 minutes? b. What is the probability of completing the exam in less than 95 minutes? c. What is the probability of completing the exam in more than 75 minutes? d. What is the probability of completing the exam...
1. The time need to complete a final examination in a college course is normally distributed...
1. The time need to complete a final examination in a college course is normally distributed with a mean of 80 minutes and a standard deviation of 10 minutes. What is the probability of completing the exam in less than 60 minutes? What is the probability of completing the exam in less than 95 minutes? What is the probability of completing the exam in more than 75 minutes? What is the probability of completing the exam within 60 to 75...
1. The time need to complete a final examination in a college course is normally distributed...
1. The time need to complete a final examination in a college course is normally distributed with a mean of 80 minutes and a standard deviation of 10 minutes. What is the probability of completing the exam in less than 60 minutes? What is the probability of completing the exam in less than 95 minutes? What is the probability of completing the exam in more than 75 minutes? What is the probability of completing the exam within 60 to 75...
The time needed to complete a final examination in a particular college course is normally distributed with a mean of 80 minutes and a standard deviation of 10 minutes. Answer the following questions.
  The time needed to complete a final examination in a particular college course is normally distributed with a mean of 80 minutes and a standard deviation of 10 minutes. Answer the following questions. (a) What is the probability of completing the exam in one hour or less? (Round your answer to four decimal places.) (b) What is the probability that a student will complete the exam in more than 60 minutes but less than 75 minutes? (Round your answer...
The time needed to complete a final t3st in a particular college course used to be...
The time needed to complete a final t3st in a particular college course used to be with a mean of 80 minutes and a standard deviation of 10 minutes. a. What is the probability of completing the 3xam in one hour or less? b. What is the probability that a student will complete the 3xam in more than 60 minutes but less than 75 minutes?
Assume that the time needed to complete a midterm exam for a particular course is normally...
Assume that the time needed to complete a midterm exam for a particular course is normally distributed with a mean of 90 minutes and a standard deviation of 15 minutes. 5- What percentage of the class is expected to complete the exam within 60 minutes? 6- What percentage of the class is predicted to NOT complete the exam within 115 minutes? 7- If the time limit is 100 minutes and there are 200 students in the class, how many of...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT