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

Author Question: A sample of 13 college professors has a mean age of 30 years and a standard deviation of 5 years. ... (Read 244 times)

burton19126

  • Hero Member
  • *****
  • Posts: 532
A sample of 13 college professors has a mean age of 30 years and a standard deviation of 5 years. Suppose that the sample is enlarged to 15 college professors, by including two additional professors that are each 30 years old. Will the standard deviation increase, decrease, or stay the same, and why?

Question 2

The following data represent the number of children in a sample of 10 families from a certain community: 4, 2, 1, 1, 5, 3, 0, 1, 0, and 2.
 a. Compute the range.
  b. Compute the variance.
  c. Compute the standard deviation.
  d. Compute the coefficient of variation.
  e. Explain why in this case range > variance > standard deviation > coefficient of variation.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

mfedorka

  • Sr. Member
  • ****
  • Posts: 324
Answer to Question 1

The new standard deviation will be smaller than the original one because the two new professors' ages don't deviate from the mean, but they add two more observations to the data set, bringing down the average deviation from the mean. The new standard deviation actually is s = 4.643.

Answer to Question 2

a. 5
b. 2.77
c. 1.66
d. 0.87
e. The range is the difference between the largest and smallest observation, which compares the numbers to each other; the variance is in essence the average squared deviation from mean, which compares the numbers to the mean. The standard deviation is less than the variance because it's the square root of a number larger than one. The coefficient of variation is even smaller because the mean is larger than the standard deviation.




burton19126

  • Member
  • Posts: 532
Reply 2 on: Jun 24, 2018
Excellent


pangili4

  • Member
  • Posts: 346
Reply 3 on: Yesterday
Wow, this really help

 

Did you know?

Medication errors are three times higher among children and infants than with adults.

Did you know?

The toxic levels for lithium carbonate are close to the therapeutic levels. Signs of toxicity include fine hand tremor, polyuria, mild thirst, nausea, general discomfort, diarrhea, vomiting, drowsiness, muscular weakness, lack of coordination, ataxia, giddiness, tinnitus, and blurred vision.

Did you know?

Blood is approximately twice as thick as water because of the cells and other components found in it.

Did you know?

Cocaine was isolated in 1860 and first used as a local anesthetic in 1884. Its first clinical use was by Sigmund Freud to wean a patient from morphine addiction. The fictional character Sherlock Holmes was supposed to be addicted to cocaine by injection.

Did you know?

On average, the stomach produces 2 L of hydrochloric acid per day.

For a complete list of videos, visit our video library