This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: A random sample of 81 automobiles traveling on a section of an interstate showed an average speed of ... (Read 266 times)

go.lag

  • Hero Member
  • *****
  • Posts: 667
on: Jun 24, 2018
A random sample of 81 automobiles traveling on a section of an interstate showed an average speed of 60 mph. The distribution of speeds of all cars on this section of highway is normally distributed, with a standard deviation of 13.5 mph. If the sample size was 25 (other factors remain unchanged), the interval for  would _____.
 a. not change
  b. become narrower
  c. become wider
  d. become zero

Question 2

The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a standard deviation of 2 ounces. What is the probability that a randomly selected item will weigh between 11 and 12 ounces?
 a. .4772
  b. .4332
  c. .9104
  d. .0440


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

underwood14

  • Sr. Member
  • ****
  • Posts: 346
Reply #1 on: Jun 24, 2018
Answer to Question 1

c

Answer to Question 2

d


go.lag

  • Member
  • Posts: 667
Reply 2 on: Jun 24, 2018
Excellent

fatboyy09

  • Member
  • Posts: 358
Reply 3 on: Yesterday
:D TYSM

« previous next »
 

Did you know?

Since 1988, the CDC has reported a 99% reduction in bacterial meningitis caused by Haemophilus influenzae, due to the introduction of the vaccine against it.

Did you know?

Many of the drugs used by neuroscientists are derived from toxic plants and venomous animals (such as snakes, spiders, snails, and puffer fish).

Did you know?

Congestive heart failure is a serious disorder that carries a reduced life expectancy. Heart failure is usually a chronic illness, and it may worsen with infection or other physical stressors.

Did you know?

Glaucoma is a leading cause of blindness. As of yet, there is no cure. Everyone is at risk, and there may be no warning signs. It is six to eight times more common in African Americans than in whites. The best and most effective way to detect glaucoma is to receive a dilated eye examination.

Did you know?

Liver spots have nothing whatsoever to do with the liver. They are a type of freckles commonly seen in older adults who have been out in the sun without sufficient sunscreen.

Sample Exercise Program for Healthy Older Adults (cont.) Sample Exercise Program for Healthy Older Adults (cont.)
A) Sagittal section of the brain; (B) lateral view of the brain. A) Sagittal section of the brain; (B) lateral view of the brain.
How to find the average value of a function (Part 2) How to find the average value of a function (Part 2)
Sagittal section of eye and its accessory structures Sagittal section of eye and its accessory structures
A cross section of muscle showing the molecular organization within the muscle fiber. In normal musc A cross section of muscle showing the molecular organization within the muscle fiber. In normal musc
Yearly growth of tree trunk (cross-section) Yearly growth of tree trunk (cross-section)
Video: Physiology of Asthma

For a complete list of videos, visit our video library