Statistics for Decision Making: 1. Question :     (TCO 1) What method of data collection would you use to collect data for a study of the salaries of college professors at a particular college?

2. Question :      (TCO 2) The chances of winning the California Lottery are 1 in 22 million. This statement describes

3. Question :      (TCO 2) The colors of automobiles on a used car lot are

4. Question :      (TCO 1) A lobbyist for a major airspace firm assigns a number to each legislator and then uses a computer to randomly generate ten numbers. The lobbyist contacts the legislators corresponding to these numbers. What sampling technique is used?

5. Question :      (TCO 2) A recent survey by a national women’s association showed that the average salary of 3500 of its 65,000 membership was $73,000. This number is a

6. Question :      (TCO 2) Which is used more often?

7. Question :      (TCO 2) Suppose the standard deviation is 13.1. What is the variance?

8. Question :      (TCO 10) These data represent the ages of drivers and the number of accidents reported for each age group in Pennsylvania for a selected year. (Age, Number of Accidents) (16, 6605), (17, 8932), (18, 8506), (19, 7349), (20, 6458), (21, 5974)

 9. Question :     (TCO 9) A researcher found a significant relationship between a student’s IQ, a, the grade point average, b, and the score, y, on the verbal section of the SAT test. The relationship can be represented by the multiple regression equation y = 250 + 1.5a + 80b. Predict the SAT verbal score (to the nearest whole number) of a student whose IQ is 130 and grade point average is 2.2.

10. Question :    (TCO 9) Interpret an r value of 0.11.

11. Question :    (TCO 3) Use this table to answer the questions………….

1. Identify the class width.

2. Identify the midpoint of the first class.

3. Identify the class boundaries of the first class.

4. Give the relative frequency for each class.

Statistics for Decision Making

12. Question :    (TCO 3) The heights in inches of 18 randomly selected adult males in LA are listed as: 70, 69, 72, 57, 70, 66, 69, 73, 80, 68, 71, 68, 72, 67, 58, 74, 81, 72.

 

MATH 221 Week 5 Quiz

 1. Question :     (TCO 4) Three members of a club will be selected to serve as officers. The first person selected will be president, the second person will be vice-president and the third will be secretary/treasurer. How many ways can these officers be selected if there are 30 club members?

 2. Question :     (TCO 4) Which of the following cannot be a probability?

3. Question :     (TCO 4) List the sample space of rolling a 6 sided die.

4. Question :     (TCO 4) What is the probability of choosing a queen on the 2nd draw if the first was a queen (without replacement)?

5. Question :      (TCO 4) A nursing class has 13 women and 18 men. If a student is chosen randomly to be the team leader, what is the probability the student is a woman?

6. Question :      (TCO 4) Compute the following: 3! ÷ (0! * 3!)

7. Question :     (TCO 5) Decide whether the experiment is a binomial, Poisson, or neither based on the information given. Each week a man plays a game in which he has a 21% chance of winning. The random variable is the number of times he wins in 64 weeks.

 8. Question :     (TCO 5) Given a Poisson distribution with mean = 4. Find P(X < 3).

 9. Question :     (TCO 5) Given the random variable X = {7, 8} with P(7) = 0.7 and P(8) = 0.3. Find E(X).

10. Question :   (TCO 5) If X = {-1, 12, 3, -4} and P(-1) = 0.3, P(12) = 0.1, P(3) = 0.2, and P(-4) = 0.4, can distribution of the random variable X be considered a probability distribution?

11. Question :   (TCO 5) If X = {2, 6, 10, 14} and P(2) = 0.2, P(6) = 0.3, P(10) = 0.4, and P(14) = 0.1, can distribution of the random variable X be considered a probability distribution?

 12. Question :   (TCO 5) The number of shoes in your closet represents what kind of distribution?

 13. Question :   (TCO 5) Your baby’s height represents what kind of distribution?

14. Question :    (TCO 5) The amount of posts in our class at a given time represents what kind of distribution?

Explanatory

1.Question :      (TCO 5) We have a binomial experiment with p = 0.4 and n = 2.

(1) Set up the probability distribution by showing all x values and their associated probabilities.

(2) Compute the mean, variance, and standard deviation.

 2.Question :      (TCO 4) What is the probability that the student is a sophomore given he doesn’t carry a credit card?

3.Question :       (TCO 4) Some students were asked if they carry a credit card. Here are the responses.

4.Question :       (TCO 4) What is the probability that the student is a sophomore and doesn’t carry a credit card?

 

MATH 221 Week 7 Quiz

1. Question :      (TCO 6) In the standard normal distribution, the standard deviation is always

2. Question :      (TCO 6) The area under a normal curve with mu = 8 and sigma = 3 is

3. Question :      (TCO 6) If Larry gets a 70 on a physics test where the mean is 65 and the standard deviation is 5.8, where does he stand in relation to his classmates?

4. Question :      (TCO 6) In a normal distribution with mu = 25 and sigma = 6, what number corresponds to z = 3?

5. Question :      (TCO 6) Let’s assume you have taken 100 samples of size 64 each from a normally distributed population. Calculate the standard deviation of the sample means if the population’s variance is 49.

 6. Question :     (TCO 6) The area to the left of ‘z’ is 0.9976. What z-score corresponds to this area?

7. Question :      (TCO 6) Find P(9 < x < 22) when mu = 20 and sigma = 5.

8. Question :      (TCO 7) What is the critical z-value that corresponds to a confidence level of 86%?

 9. Question :     (TCO 7) Compute the population mean margin of error for a 90% confidence interval when sigma is 4 and the sample size is 36.

10. Question :   (TCO 7) A standard IQ test has a mean of 98 and a standard deviation of 16. We want to be 99% certain that we are within 8 IQ points of the true mean. Determine the sample size.

 11. Question :   (TCO 7) A private medical clinic wants to estimate the true mean annual income of its patients. The clinic needs to be within $500 of the true mean. The clinic estimates that the true population standard deviation is around $2,300. If the confidence level is 95%, find the required sample size in order to meet the desired accuracy.

12. Question :    (TCO 7) An auditor wants to estimate what proportion of a bank’s commercial loan files are incomplete. The auditor wants to be within 10% of the true proportion when using a 95% confidence level. How many files must the auditor sample? No estimate of the proportion is available, so use 0.5 for the population proportion.

Explanatory       

1. Question :      (TCO 7) Interpret a 95% confidence interval of (3.355, 3.445) for the population mean.

2. Question :      (TCO 7) A nursing school wants to estimate the true mean annual income of its alumni. It randomly samples 200 of its alumni. The mean annual income was $52,500 with a standard deviation of $1,800. Find a 95% confidence interval for the true mean annual income of the nursing school alumni. Write a statement about the confidence level and the interval you find.

 

3. Question :      (TCO 7) An auditor wants to estimate what proportion of a bank’s commercial loan files are incomplete. The auditor randomly samples 60 files and finds 12 are incomplete. Using a 95% confidence interval, estimate the true proportion of incomplete files for ALL the bank’s commercial loans. Write a statement about the confidence level and the interval you find.