Author Question: Whenever the population standard deviation is unknown, which distribution is used in developing an ... (Read 90 times)

RODY.ELKHALIL

  • Hero Member
  • *****
  • Posts: 591
Whenever the population standard deviation is unknown, which distribution is used in developing an interval estimate for a population mean?
 a. standard distribution
  b. z distribution
  c. binomial distribution
  d. t distribution

Question 2

The life expectancy of a particular brand of tire is normally distributed with a mean of 40,000 and a standard deviation of 5,000 miles. What is the probability that a randomly selected tire will have a life of exactly 47,500 miles?
 a. .4332
  b. .9332
  c. .0668
  d. 0



triiciiaa

  • Sr. Member
  • ****
  • Posts: 349
Answer to Question 1

d

Answer to Question 2

d



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

Elderly adults are living longer, and causes of death are shifting. At the same time, autopsy rates are at or near their lowest in history.

Did you know?

Children of people with alcoholism are more inclined to drink alcohol or use hard drugs. In fact, they are 400 times more likely to use hard drugs than those who do not have a family history of alcohol addiction.

Did you know?

Alzheimer's disease affects only about 10% of people older than 65 years of age. Most forms of decreased mental function and dementia are caused by disuse (letting the mind get lazy).

Did you know?

Today, nearly 8 out of 10 pregnant women living with HIV (about 1.1 million), receive antiretrovirals.

Did you know?

Patients who cannot swallow may receive nutrition via a parenteral route—usually, a catheter is inserted through the chest into a large vein going into the heart.

For a complete list of videos, visit our video library