This topic contains a solution. Click here to go to the answer

Author Question: The residents of one town are classified by a social scientist as follows. Lower income: 4320 ... (Read 138 times)

ts19998

  • Hero Member
  • *****
  • Posts: 531
The residents of one town are classified by a social scientist as follows.
 
  Lower income: 4320
   Middle income: 1520
   Upper income: 2160
 
  The scientist wishes to pick a sample of 200 of the residents for a study. Describe a method for selecting the sample which involves stratified sampling with proportional allocation.

Question 2

The owner of a farmer's market was interested in determining how many oranges a person buys when they buy oranges.
 
  He asked the cashiers over a weekend to count how many oranges a person bought when they bought oranges and record this number for analysis at a later time. The data is given below in the table. The random variable x represents the number of oranges purchased and P(x) represents the probability that a customer will buy x oranges. Determine the variance of the number of oranges purchased by a customer.
 
  x 1 2 3 4 5 6 7 8 9 10
  P(x) 0.05 0.19 0.20 0.25 0.12 0.10 0 0.08 0 0.01
 
  A) 3.97 B) 1.95 C) 0.56 D) 3.57



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

ashely1112

  • Sr. Member
  • ****
  • Posts: 347
Answer to Question 1

Answers will vary. Possible answer: Proportional allocation dictates that the number of lower income, middle income, and upper income residents selected by the scientist be 108, 38, and 54, respectively. Thus the scientist can obtain a stratified sample of 200 residents as follows: Number the lower income residents from 1 through 4320 and use table of random numbers to randomly select 108 of the 4320 lower income residents; number the middle income residents from 1 to 1520 and use a table of random numbers to randomly select 38 of the 1520 middle income residents; number the upper income residents from 1 to 2160 and use a table of random numbers to randomly select 54 of the 2160 upper income residents.

Answer to Question 2

D




ts19998

  • Member
  • Posts: 531
Reply 2 on: Jul 25, 2018
Thanks for the timely response, appreciate it


xiazhe

  • Member
  • Posts: 331
Reply 3 on: Yesterday
Great answer, keep it coming :)

 

Did you know?

Stroke kills people from all ethnic backgrounds, but the people at highest risk for fatal strokes are: black men, black women, Asian men, white men, and white women.

Did you know?

For pediatric patients, intravenous fluids are the most commonly cited products involved in medication errors that are reported to the USP.

Did you know?

Over time, chronic hepatitis B virus and hepatitis C virus infections can progress to advanced liver disease, liver failure, and hepatocellular carcinoma. Unlike other forms, more than 80% of hepatitis C infections become chronic and lead to liver disease. When combined with hepatitis B, hepatitis C now accounts for 75% percent of all cases of liver disease around the world. Liver failure caused by hepatitis C is now leading cause of liver transplants in the United States.

Did you know?

All patients with hyperparathyroidism will develop osteoporosis. The parathyroid glands maintain blood calcium within the normal range. All patients with this disease will continue to lose calcium from their bones every day, and there is no way to prevent the development of osteoporosis as a result.

Did you know?

Oliver Wendell Holmes is credited with introducing the words "anesthesia" and "anesthetic" into the English language in 1846.

For a complete list of videos, visit our video library