Author Question: A random sample of 25 observations was selected from a normally distributed population. The average ... (Read 98 times)

darbym82

  • Hero Member
  • *****
  • Posts: 570
A random sample of 25 observations was selected from a normally distributed population. The average in the sample was 84.6 with a variance of 400.
 a. Construct a 90 confidence interval for .
  b. Construct a 99 confidence interval for .
  c. Discuss why the 90 and 99 confidence intervals are different.
  d. What would you expect to happen to the confidence interval in part (a) if the sample size was increased? Be sure to explain your answer.

Question 2

If you are deciding to buy either machine A, B, or C with the objective of minimizing the sum of labor, material and utility costs, you are dealing with a single-criterion decision.
  Indicate whether the statement is true or false



kjohnson

  • Sr. Member
  • ****
  • Posts: 330
Answer to Question 1

a. 77.756 to 91.444
b. 73.412 to 95.788
c. As the level of confidence increases, the confidence interval gets wider.
d. Decrease in width since the margin of error decreased.

Answer to Question 2

T



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

The top 10 most important tips that will help you grow old gracefully include (1) quit smoking, (2) keep your weight down, (3) take supplements, (4) skip a meal each day or fast 1 day per week, (5) get a pet, (6) get medical help for chronic pain, (7) walk regularly, (8) reduce arguments, (9) put live plants in your living space, and (10) do some weight training.

Did you know?

Blastomycosis is often misdiagnosed, resulting in tragic outcomes. It is caused by a fungus living in moist soil, in wooded areas of the United States and Canada. If inhaled, the fungus can cause mild breathing problems that may worsen and cause serious illness and even death.

Did you know?

People with alcoholism are at a much greater risk of malnutrition than are other people and usually exhibit low levels of most vitamins (especially folic acid). This is because alcohol often takes the place of 50% of their daily intake of calories, with little nutritional value contained in it.

Did you know?

Of the estimated 2 million heroin users in the United States, 600,000–800,000 are considered hardcore addicts. Heroin addiction is considered to be one of the hardest addictions to recover from.

Did you know?

There can actually be a 25-hour time difference between certain locations in the world. The International Date Line passes between the islands of Samoa and American Samoa. It is not a straight line, but "zig-zags" around various island chains. Therefore, Samoa and nearby islands have one date, while American Samoa and nearby islands are one day behind. Daylight saving time is used in some islands, but not in others—further shifting the hours out of sync with natural time.

For a complete list of videos, visit our video library