Devry MATH221 Week 2 Homework Latest 2021 June

MATH221 Statistics for Decision Making

Week 2 Homework

Question 1 Given the following information, find the probability that a randomly selected student will be very short. Number of students who are very short: 45, short: 60, tall: 82, very tall: 21

  28.8%

  21.6%

  21.0%

  39.4%

 Question 2Given the following information, find the probability that a randomly selected dog will be a poodle. Number of dogs who are poodles: 31, golden retrievers: 58, beagles: 20, pugs: 38

  58.0%

  42.0%

  39.5%

  21.1%

Question 3Given that there is a 21% chance it will rain on any day, what is the probability that it will rain on the first day and be clear (not rain) on the next two days?

  13.1%

  36.2%

  16.6%

  21.0%

Question 4Consider the following table. What is the probability of no?

                Red        Blue       Total

Yes         15           21           36

No          38           13           51

Total      53           34           87

  13/51

  51/34

  13/34

  51/87

 Question 5Consider the following table. What is probability of yes, given green?

 

                Red        Blue       Green   Total

Yes         33           44           14           91

No          18           5              28           51

Total      51           49           42           142

  51/142

  14/42

  42/142

  14/91

 Question 6In a sample of 350 customers, 125 say that service is poor. You select two customers without replacement to get more information on their satisfaction. What is the probability that both say service is poor?

  14.29%

  12.76%

  12.69%

  41.67%

 Question 7Some days, the CEO holds meetings and some days the CEO is wearing blue shoes. How would you most likely classify these events?

  Dependent

  Independent

 Question 8Of the shirts produced by a company, 6.5% have loose threads, 9.5% have crooked stitching, and 3% have loose threads and crooked stitching. Find the probability that a randomly selected shirt has loose threads or has crooked stitching.

  19.0%

  13.0%

  12.5%

  16.0%

 Question 9Randomly select a customer that is a frequent shopper at our store. Randomly select a customer who does not know the store’s location. Are these events mutually exclusive?

  Non-mutually exclusive events

  Mutually exclusive events

 Question 10In a sample of 800 adults, 242 said that they liked sugar cereals. Three adults are selected at random without replacement. Find the probability that all three like sugar cereals.

  2.77%

  2.70%

  2.73%

  2.74%

 Question 11A sock drawer has 17 folded pairs of socks, with 5 pairs of white, 8 pairs of black and 4 pairs of blue.  What is the probability, without looking in the drawer, that you will first select and remove a black pair, then select either a blue or a white pair?

  24.91%

  47.06%

  52.94%

  26.47%

Question 12An investment advisor believes that there is a 74% chance of making money by investing in a specific stock. If the stock makes money, then there is a 54% chance that among those making money, they would also get a dividend. Find the probability that the investor makes money and receive a dividend.

  20%

  40%

  54%

  37%

 Question 13An investment advisor believes that there is a 60% chance of making money by investing in a specific stock. If the stock makes money, then there is a 50% chance that among those making money, they would also get a dividend. Find the probability that the investor makes money but does not receive a dividend.

  50%

  30%

  60%

  10%

 Question 14A smartphone company found in a survey that 17% of people did not own a smartphone, 18% owned a smartphone only, 29% owned a smartphone and only a tablet, 21% owned a smartphone and only a computer, and 15% owned all three. If a person were selected at random, what is the probability that the person would own a smartphone only or a smartphone and computer?

  21%

  39%

  47%

  61%

 Question 15Match the terms and their definitions

0 and 1

Probability is between

1 – P(E)

The occurrence of one event does not affect the occurrence of the other

Cannot occur at the same time

Probability of an event given that another event has occurred