Statistic Question

We have a pond with 50 fish including 25 trout, 10 tuna, and 15 salmon.  Dr. Lozier reaches into the pond and grabs one at random, what is the probability she grabs a salmon?

• 0.15
• 0.30
• 0.25
• 0.50

In a sample of people’s heights where you know the mean is 55 inches and the standard deviation is 5 inches, what is the z-score for a height of 47.5 inches?

• 1
• -1
• 2
• -1.5

In a standard/normal distribution, what percentage of data falls between a z-score of -1 and 2?

• 82
• 34
• 96
• 14

What does sampling with replacement mean when discussing probability?

• It means we put back whatever is taken out of the population
• It means we treat everything as dependent

If heights of 3rd graders follow a normal distribution with a mean of 52 inches and a standard deviation of 2.5 inches, what is the z score of a 3rd grader who is 47 inches tall? 

• -5
• -2
• 2
• 5

A national achievement test is administered annually to 3rd graders. The test has a mean score of 100 and a standard deviation of 15. If Jane's z-score is 1.20, what was her score on the test?

• 82
• 88
• 100
• 118

The mean life of a tire is 30,000 km. The standard deviation is 2000 km.

Then, 68% of all tires will have a life between ___________ km and __________ km.

•  28,000 km and 32,000 km.
• 24,000 km and 34,000 km.
• 26,000 km and 34,000 km.
• 27,000 km and 31,000 km.