Alg 2 AB U12 Day 6 - Review

  1. Find the mean, median, and mode for the data set

43435543544251

  1. Given: 56, 78, 125, 34, 67, 91, 20. Determine if there are any outliers.
  2. A study shows that 42% of families in a community watch TV during dinner. Suppose you select 10 families at random.
  3. Find the probability that exactly 3 watch TV during dinner.
  4. Find the probability that at least 8 watch TV during dinner.
  5. Given the set of values below, at what percentiles are 78 and 81?

43586478788189899193

  1. At a high school, 30% of the students buy class rings. You select five students at random. Find
  2. P(exactly two buy rings)
  3. P(at least two buy rings)
  4. A student guesses the answers to three questions on a true or false test. Find the probability that the student guesses at least one of the questions correctly.
  5. A set of data is normally distributed with a mean of 29 and a standard deviation of 4. Find the percent of data within each interval.
  6. From 25 to 33b. from 21-25

c. greater than 29d. less than 21

Age of Respondent / Weekly hours
On Facebook
0-4 / 5 or more
30 / 7 / 18
<30 / 13 / 12
  1. In a survey of people in New York City, 39% of people have a car and have had a car. 61% do not have a car now. 86% have had a car and 14% do not have a car now and have never had a car. Find the probability that a person chosen at random has never had a car, given that they do not have a car now.
  2. Use the chart to the right to answer the following questions regarding hours spent on facebook per week:

a) Probability that someone spends 5 or more hours on facebook

b)Probability that someone under 30 spends 5 or more hours on facebook

c)Probability that someone who spends 0-4 hours per week on facebook is over the age of 30.

  1. 12% of students at WestHigh School play in the band and also play a sport. 31% of the students play in the band and 43% play a sport. What is the probability that someone who plays in the band also plays a sport?
  1. What is standard deviation? What is the equation to find standard deviation?
  1. Given the following set of data, find the standard deviation by hand then check your answer on your calculator.

7 5 9 4 5

b. Given the following set of data, use your calculator to find the standard deviation.

$1.95$1.27$1.81$1.33$1.30$0.99$1.63$1.49$1.39$1.25$1.50

  1. Find the probability of 13 successes in 24 trials, given the probability of success is 0.6 for each trial.
  2. A data set has a mean of 25 and a standard deviation of 5. Find the z-score of 11.
  3. Marie knows that she has a 73% chance of getting into each college that she applies to. If she applies to 6 colleges, what is the probability that:
  4. She will get into all 6 of them?
  5. She will get into at least 4 of them?
  6. She will not get into any of them?
  7. She will get into no more than 3 of them?
  8. Suppose that the average temperature of a Philadelphia July day is 83 degrees with a standard deviation of 2 degrees. On how many days in July can you expect the temperature to be above 87? On how many days can you expect the temperature to be between 79 and 85 degrees?

Answers:

1. mean 47.286, median 43, mode 432. no outliers

3. a. .196b. .017

4. 30th and 50th5. a. .3 or 30% b. .47178 or 47.178% 6. .875 or 87.5%

7. a. 68% b. 13.5% c. 50% d. 2.5%8. 9. a. 3/5 b. 12/25 c.7/20

10. 11. a. 1.789 b. .259 12. .13674 or 13.674% 13. -2.8

14. a).151b) .798c) 3.874 x 10-4 (almost zero!)d) .201

15. a) 31 days (.025) = .775 or 1 dayb) 31 days (.815) = 25.3 (about 25 days)