Author Question: In developing an interval estimate of the population mean, if the population standard deviation is ... (Read 117 times)

jasdeep_brar

  • Hero Member
  • *****
  • Posts: 569
In developing an interval estimate of the population mean, if the population standard deviation is unknown _____.
 a. it is impossible to develop an interval estimate
  b. a sample proportion can be used
  c. the sample standard deviation and t distribution can be used
  d. None of the answers is correct.

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 at least 30,000 miles?
 a. .4772
  b. .9772
  c. .0228
  d. None of the answers is correct.



HandsomeMarc

  • Sr. Member
  • ****
  • Posts: 360
Answer to Question 1

c

Answer to Question 2

b



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

It is widely believed that giving a daily oral dose of aspirin to heart attack patients improves their chances of survival because the aspirin blocks the formation of new blood clots.

Did you know?

Not getting enough sleep can greatly weaken the immune system. Lack of sleep makes you more likely to catch a cold, or more difficult to fight off an infection.

Did you know?

People about to have surgery must tell their health care providers about all supplements they take.

Did you know?

According to the FDA, adverse drug events harmed or killed approximately 1,200,000 people in the United States in the year 2015.

Did you know?

ACTH levels are normally highest in the early morning (between 6 and 8 A.M.) and lowest in the evening (between 6 and 11 P.M.). Therefore, a doctor who suspects abnormal levels looks for low ACTH in the morning and high ACTH in the evening.

For a complete list of videos, visit our video library