Question

The time a student spends learning a computer software package is normally distributed with a mean...


The time a student spends learning a computer software package is normally distributed with a mean of 8 hours and a standard deviation of 1.5 hours. A student is selected at random.
a)What is the probability that the student spends at least 6 hours learning the software package?
b) What is the probability that the student spends between 6.5 and 8.5 hours learning the software package?
c) If only 7% of the students spend more than k hours learning the software package, determine the value of k.

Homework Answers

Answer #1

Solution:-

Mean = 8, S.D = 1.5

a) The probability that the student spends at least 6 hours learning the software package is 0.9087

x = 6

By applying normal distribution:-

z = - 1.33

P(z > - 1.33) = 0.9087

b) The probability that the student spends between 6.5 and 8.5 hours learning the software package is 0.4717.

x1 = 6.50

x2 = 8.50

By applying normal distribution:-

z1 = -1.0

z2 = 0.333

P( -1.0 < z < 0.333) = P(z > -1.0) - P(z > 0.333)

P( -1.0 < z < 0.333) = 0.8413 - 0.3696

P( -1.0 < z < 0.333) = 0.4717

c) If only 7% of the students spend more than k hours learning the software package, then the value of k is 10.214

p-value for the top 7% = 1 - 0.07 = 0.93

z-score for the p-value = 1.476

By applying normal distribution:-

x = 10.214

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
The times per week a student uses a lab computer are normally​ distributed, with a mean...
The times per week a student uses a lab computer are normally​ distributed, with a mean of 6.1 hours and a standard deviation of 1.3 hours. A student is randomly selected. Find the following probabilities. ​(a) Find the probability that the student uses a lab computer less than 4 hours per week. ​(b) Find the probability that the student uses a lab computer between 7 and 8 hours per week. ​(c) Find the probability that the student uses a lab...
The times per week a student uses a lab computer are normally​ distributed, with a mean...
The times per week a student uses a lab computer are normally​ distributed, with a mean of 6.3 hours and a standard deviation of 1.2 hours. A student is randomly selected. Find the following probabilities. ​(a) Find the probability that the student uses a lab computer less than 5 hours per week. ​(b) Find the probability that the student uses a lab computer between 6 and 8 hours per week. ​(c) Find the probability that the student uses a lab...
The times per week a student uses a lab computer are normally​ distributed, with a mean...
The times per week a student uses a lab computer are normally​ distributed, with a mean of 6.2 hours and a standard deviation of 1.3 hours. A student is randomly selected. Find the following probabilities. ​(a) Find the probability that the student uses a lab computer less than 4 hours per week. ​(b) Find the probability that the student uses a lab computer between 6 and 8 hours per week. ​(c) Find the probability that the student uses a lab...
It has been determined that the mean amount of time that computer science majors spend on...
It has been determined that the mean amount of time that computer science majors spend on homework each week is approximately normally distributed with a mean of 15.2 hours and standard deviation 3.1 hours. What is the probability that a randomly selected computer science major will spend more than 14.5 hours on homework in a given week?
Student scores on the Stats final exam are normally distributed with a mean of 75 and...
Student scores on the Stats final exam are normally distributed with a mean of 75 and a standard deviation of 6.5 Find the probability of the following: (use 4 decimal places) a.) The probability that one student chosen at random scores above an 80. b.) The probability that 10 students chosen at random have a mean score above an 80. c.) The probability that one student chosen at random scores between a 70 and an 80. d.) The probability that...
For a certain very large group of students, test scores are normally distributed with a mean...
For a certain very large group of students, test scores are normally distributed with a mean of 70 and a standard deviation of 8. A student will receive an A if he gets at least a 92, and must earn at least a 67 in order to pass. a. What is the probability that a student selected at random will get an A on the test? b. What is the probability that a random sample of 20 students will have...
The time, in minutes spent texting in class, is approximately normally distributed with a mean of...
The time, in minutes spent texting in class, is approximately normally distributed with a mean of 6.2 minutes and a standard of 1.6 minutes. The distance, in city blocks, that a student must travel to get from one class to the next has a Chi-squared distribution with 4 degrees of freedom. (The standard city block is approximately 400 feet long) 1) What is the probability that the average time spent texting in a class of 12 random students is between...
Suppose that the heights of students are normally distributed with mean 67 inches and standard deviation...
Suppose that the heights of students are normally distributed with mean 67 inches and standard deviation 3 inches. (a) What is the probability that a randomly chosen student is at least 69 inches tall? (b) What is the probability that the mean height of a random sample of 5 students is at least 69 inches? (c) What is the probability that the mean height of a random sample of 20 students is at least 69 inches?
The times that a person spends in the shower are normally distributed with a mean of...
The times that a person spends in the shower are normally distributed with a mean of 12.5 minutes and a standard deviation of 3.5 minutes. If 25 people is selected, find the probability that the mean time taken by him/her is less than 14 minutes?
The times that a person spends in the shower are normally distributed with a mean of...
The times that a person spends in the shower are normally distributed with a mean of 12.5 minutes and a standard deviation of 3.5 minutes. If 9 people is selected, find the probability that the mean time taken by him/her is greater than 15.2 minutes?
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT
Active Questions
  • Number of Children Salary 2 or fewer children more than 2 children high salary 0.13 0.02...
    asked 13 minutes ago
  • Concord Company ended its fiscal year on July 31, 2022. The company’s adjusted trial balance as...
    asked 19 minutes ago
  • In a simple random sample of 1180 U.S. adults from a large population, it is found...
    asked 26 minutes ago
  • Sage Corporation manufactures two products with the following characteristics. Unit Contribution Margin Machine Hours Required for...
    asked 29 minutes ago
  • For the probability distribution below find the mean, variance, and standard deviation. ? P(?) ?P (?)...
    asked 36 minutes ago
  • The battery manufacturer that makes the batteries for the municipal police department’s body cameras asserts its...
    asked 44 minutes ago
  • the dean of student life at Gonzaga University reported recently that 0.75 of all Gonzaga students...
    asked 52 minutes ago
  • Consider two grounded conducting plates, located parallel to the x-y plane at z = 0 and...
    asked 54 minutes ago
  • Describe micropayments in detail. Discuss three different situations where micropayments could occur.
    asked 1 hour ago
  • A random digit dialing telephone survey of 908 drivers asked, "Recalling the last ten traffic lights...
    asked 1 hour ago
  • 1) A study of 150 apple trees showed that the average number of apples per tree...
    asked 1 hour ago
  • Consider a one-dimensional material “nanowire” with normal parabolic energy-momentum relationship. Derive the expression for the density...
    asked 1 hour ago