The Test of English as a Foreign Language (TOEFL) is required by most universities to help in their admissiondecisions on international students. From past records at a certain university, these scores are approximatelynormally distributed with a mean of 500 and a variance of 6,400. If an international student's application is selectedat random,(a) what is the probability that the student's TOEFL score is at most 440?(b) what is the probability that the student's TOEFL score is at least 510?(c) what is the probability that the student's TOEFL score is equal to the mean score?(d) what is the probability that the student's TOEFL score is between 465 and 515?

As per the bartleby guidelines for more than three parts only three parts has to be solved. Please…

Answered: The Test of English as a Foreign…

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

See similar textbooks

Similar questions

What is the Discrete Variance when sample size is 82 with a probability of 0.82?
The mean height of men in the US (ages 20-29) is 69.6 inches with a standard deviation of 4 inches. If a random sample of 36 men is chosen from this age group, what is the probability that a sample mean height is less than 70 inches?
A quality control expert at LIFE batteries wants to test their new batteries. The design engineer claims they have a variance of 6724 with a mean life of 645 minutes. If the claim is true, in a sample of 152 batteries, what is the probability that the mean battery life would differ from the population mean by more than 88 minutes? Round your answer to four decimal places.
Bespin Car Rental predicts that the annual probability of one of its cars being destroyed in a crash is 1 in 100,000. If destroyed, the value of the property damage to the car equals $51,000. Assume that there are no partial losses; the car is either destroyed in a crash or suffers no loss. Show the damage loss distribution for Bespin Car Rental’s automobiles and calculate the expected value of the loss. Show the calculations for the variance and the standard deviation.
The average fuel efficiency of U.S. light vehicles (cars, SUVs, minivans, vans, and light trucks) for 2005 was 21 miles per gallon (mpg). If the standard deviation of the population was 2.8 and the gas ratings were normally distributed, (a) what is the probability that the mean mpg for a random sample of 25 light vehicles is under 18? (b) between 20 and 24?
Last year, a person wrote 129 129 checks. Let the random variable x represent the number of checks he wrote in one day, and assume that it has a Poisson distribution. What is the mean number of checks written per day? What is the standard deviation? What is the variance?
The senior high school department of KsKC University found out that the final grade of 500 grade 12 students is normally distributed with a mean of 90 and standard deviation of 10. (This is an assumed data only) Grades Interpretation 97-100 With Highest Honors 95-96 With High Honor 90-94 With Honors 75-89 Average 74 and below Failed If a grade 12 student will be selected randomly to become a recipient of financial scholarship in a university, what is the probability of selecting students with a grade of 74-89?
Last year, a person wrote 118 checks. Let the random variable x represent the number of checks he wrote in one day, and assume that it has a Poisson distribution. What is the mean number of checks written per day? What is the standard deviation? What is the variance?
For runners competing in a marathon, the mean time to run a mile is 4.2 minutes with a population standard deviation of 0.6 minutes. A news reporter is looking to include statistics for his article about fast runners. At a marathon, a random sample of 31 runners was taken and the probability that the mean time to run a mile for the sample will be less than 3.9minutes was found. Was the probability a left-tail, right -tail or two-tail probability? What is the probability that the mean time to run a mile for the sample will be less than 3.9 minutes? Select the two correct answers that apply below. You may use a calculator or the portion of the z-table given below. Round your answer to three decimal places if necessary.
If the mean and standard deviation of cell sap values for healthy plants are 120 and 15 micrograms per 100 ml, respectively, what is the probability that a random sample of 50 normal plants will yield a mean between 115 and 125 micrograms per 100 ml?
Among all monthly bills from a certain credit card company, the mean amount billed was $465 and the standard deviation was $300. In addition, for 15% of the bills, the amount billed was greater than $1000. A sample of 850 bills is drawn. What is the probability that more than 150 of the sampled bills are for amounts greater than $1000? Probability =
Suppose a researcher pbserves a population of 12 people and computes SS=204. What is the variance? What is the standard deviation?

SEE MORE QUESTIONS

Recommended textbooks for you

A First Course in Probability (10th Edition)

Probability

ISBN:

9780134753119

Author:

Sheldon Ross

Publisher:

PEARSON

A First Course in Probability

Probability

ISBN:

9780321794772

Author:

Sheldon Ross

Publisher:

PEARSON

A First Course in Probability (10th Edition)

Probability

ISBN:

9780134753119

Author:

Sheldon Ross

Publisher:

PEARSON

A First Course in Probability

Probability

ISBN:

9780321794772

Author:

Sheldon Ross

Publisher:

PEARSON

SEE MORE TEXTBOOKS