1. For a population with µ=50 and σ=10,
A. What is the z-score for X=55, X=60, X=75, X=45, X=30 and X=35?
B. Find the X value that corresponds to each of the following z-scores, z=1.00, z=0.80, z=1.50, z= -0.50, z= -0.30 and z= -1.50.

2. Find the z-score corresponding to a score of X=60 for each of the following distributions.
A. µ=50 and σ=10
B. µ=50 and σ=5
C. µ=70 and σ=20
D. µ=70 and σ=5

3. For a sample with a mean of M=85, a score of X=90 corresponds to z=0.50. What is the sample standard deviation?

4. In a population of exam scores, a score of X=88 corresponds to z=+2.00 and a score of X=79 corresponds to z= -1.00. What is the means for the population? What is the standard deviation for the population?

5. A distribution with a means of µ=38 and a standard deviation of σ=20 is being transformed into a standardized distribution with µ=50 and σ=10. Find the new, standardized score for each of the following values from the original population.

A. X=48
B. X=40
C. X=30
D. X=18

PLEASE SHOW STEP BY STEP HOW YOU SOLVE THESE PROBLEMS.

A retailer's sale in widgets is normally distributed over the time of one year. The mean of the sales is 141.1 with a standard deviation of 13.62. What is the probability that he will not be able to sell 160 or more widgets in the next year?

I need help with some practice problems that were given to us, to help prepare for a quiz next week. Please provide detailed steps as to how you came by your answer (include any notes, calculations, or anything that may be pertinent to the solution).
As always, your help would be greatly appreciated!
Thanks,
E

The number of cell phone minutes used by high school seniors follows a normal distribution with a mean of 500 and a standard deviation of 50. What is the probability that a student uses fewer than 400 minutes?
a. 0
b. 0.023
c. 0.159
d. 0.977
e. none of the above

For one quantitative coures in a college with 10,000 students, it is calculated that students test scores are normally distributed with a mean of 80 and a standard deviateion of 16. Assume now we randomly select a sample of 64 students test scores.
a.) What is the probability that the average test score of the sample selecte

Setting µ = 60 and σ = 7
What is the z score of 78?
What is the z score of 45?
What is the probability of 59?
What is the probability of 62?
What score falls at z = 1.64?
What score falls at z = -1.96?
What percentage of scores are 73 or less?
What proportion of scores is between 45 and 78?

Tony Soprano and his "weasily" nephew Christopher were scheming on how they can rip off people through their waste management company. One of the ideas they are contemplating is giving everyone a much larger garbage can so they can charge higher rates. After all, the more garbage they pick up the more they can charge. Tony and C

At a large university, 500 freshmen take their final exam for their marketing course. Scores are normally distributed with a mean 79 and standard deviation 7. What is the probability of a score, X, falling between 73 and 83?

Individual scores of a placement examination are normally distributed with a mean of 84.2 and a standard deviation of 12.8.
If the score of an individual is randomly selected, find the probability that the score will be less than 90.0.
If a random sample of size n = 20 is selected, find the probability that the sample mean

A normal population has an average of 80 and a standard deviation of 14.0.
Calculate the probability of a value between 75.0 and 90.0.
Calculate the probability of a value of 75.0 or less.
Calculate the probability of a value between 55.0 and 70.0.