Stats 6.2 Homework

Note: You will see 2 variations of this question. Also Use the Table given in class, Nspire solutions do not match.

Teachers’ Salaries The average annual salary for all U.S. teachers is $47,750. Assume that the distribution is normal and the standard deviation is $5680. Find the probability that a randomly selected teacher earns

a. Between $35,000 and $45,000 a year

Note: You will see 2 variations of this question. Also Use the Table given in class, Nspire solutions do not match.

Teachers’ Salaries The average annual salary for all U.S. teachers is $47,750. Assume that the distribution is normal and the standard deviation is $5680. Find the probability that a randomly selected teacher earns

b.    More than $40,000 a year

SAT Scores The national average SAT score (for Verbal and Math) is 1028. If we assume a normal distribution with σ = 92, what is the 90th percentile score? What is the probability that a randomly selected score exceeds 1200?

Note: You will see 3 variations of this question. Also, Use the Table given in class, Nspire solutions do not match

Monthly Mortgage Payments The average monthly mortgage payment including principal and interest is $982 in the United States. If the standard deviation is approximately $180 and the mortgage payments are approximately normally distributed, find the probability that a randomly selected monthly payment is

a.    More than $1000

Note: You will see 3 variations of this question. Also, Use the Table given in class, Nspire solutions do not match

Monthly Mortgage Payments The average monthly mortgage payment including principal and interest is $982 in the United States. If the standard deviation is approximately $180 and the mortgage payments are approximately normally distributed, find the probability that a randomly selected monthly payment is

b.    More than $1475

Note: You will see 3 variations of this question. Also, Use the Table given in class, Nspire solutions do not match

Monthly Mortgage Payments The average monthly mortgage payment including principal and interest is $982 in the United States. If the standard deviation is approximately $180 and the mortgage payments are approximately normally distributed, find the probability that a randomly selected monthly payment is

c. Between $800 and $1150

Note: You will see 2 variations of this question(1 of 2). Also, Use the Table given in class, Nspire solutions do not match

New-Home Prices If the average price of a new one-family home is $246,300 with a standard deviation of $15,000, find the minimum and maximum prices of the houses that a contractor will build to satisfy the middle 80% of the market. Assume that the variable is normally distributed.

Answer Minimum for this question

Note: You will see 2 variations of this question(2 of 2). Also, Use the Table given in class, Nspire solutions do not match

New-Home Prices If the average price of a new one-family home is $246,300 with a standard deviation of $15,000, find the minimum and maximum prices of the houses that a contractor will build to satisfy the middle 80% of the market. Assume that the variable is normally distributed.

Answer Maximum for this question

Note: Use the Table given in class, Nspire solutions do not match

Product Marketing An advertising company plans to market a product to low-income families. A study states that for a particular area, the average income per family is $24,596 and the standard deviation is $6256. If the company plans to target the bottom 18% of the families based on income, find the cutoff income. Assume the variable is normally distributed.

Note: Use the Table given in class, Nspire solutions do not match

Reading Improvement Program To help students improve their reading, a school district decides to implement a reading program. It is to be administered to the bottom 5% of the students in the district, based on the scores on a reading achievement exam. If the average score for the students in the district is 122.6, find the cutoff score that will make a student eligible for the program. The standard deviation is 18. Assume the variable is normally distributed.

x=