Chapter 6 MWF Section 03

Which one should go?

• Chapter 4

• Chapter 5

• Chapter 6

• 

A sample of size 82 will be drawn from a population with mean 24 and standard deviation 9. 

Find the probability that the sample mean will be less than 26.  

• 0.978

• 0.5000
• 0.8413
• 0.0228

A sample of size 82 will be drawn from a population with mean 24 and standard deviation 9. 

2. Find the 10^th percentile of 𝑥̅.

• 24.82
• 22.73

• 23.16
• 25.43

A few lab rats are being used to study the effects of a nutritional supplement.  We know that the population they were selected from has a mean weight of 405 g and a standard deviation weight of 40 g.  We also know the population is normally distributed. 

One rat is selected at random from the population. What is the probability that it weighs more than 415 g?  

• 0.3013
• 0.5000
• 0.4013
• 0.5987

A few lab rats are being used to study the effects of a nutritional supplement.  We know that the population they were selected from has a mean weight of 405 g and a standard deviation weight of 40 g.  We also know the population is normally distributed. 

A sample of 36 rats is selected randomly.  What is the probability that the sample mean is greater than 415 g? 

• 0.1587
• 0.8413
• 0.0668

• 0.5987

A few lab rats are being used to study the effects of a nutritional supplement.  We know that the population they were selected from has a mean weight of 405 g and a standard deviation weight of 40 g.  We also know the population is normally distributed. 

For a sample of size 64, what is the probability that the sample mean is either greater than 415g or less than 390g?  

• 0.1587
• 0.8413
• 0.9759

• 0.0241

Scores on an entrance exam are Normally distributed with a mean of 600 and a standard deviation of 90.  

An applicant taking the test is selected at random. What is the probability that he or she will have a score of 450 or less?

• 0.5
• 0.9525
• 0.025
• 0.0478

Scores on an entrance exam are Normally distributed with a mean of 600 and a standard deviation of 90.  

In a sample of 100 randomly selected students taking the exam, what is the probability that the mean score is between 590 and 630?

• 0.8663

• 0.9525
• 0.025
• 0.0478

Scores on an entrance exam are Normally distributed with a mean of 600 and a standard deviation of 90.  

In a sample of 900 randomly selected students taking the exam, what is the probability that the mean score is greater than 604?

• 0.8663

• 0.0912

• 0.025
• 0.0478

What is the population proportion p for the red fishes in our pond?

• 25%

• 50%

• 60%

• 80%