Survey

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts

Discrete choice wikipedia , lookup

Transcript
```PSTAT 5A
Unit 4 Practice Problems
1. A bus arrives at a particular stop between 8:00am and 8:10am (assume the
bus is equally likely to arrive at any time within these 10 minutes). If Timmy
arrives at 8:00, what is the probability he will have to wait more than 8
minutes? …between 2.5 to 5 minutes? About how long, on average, will he
have to wait for the bus?
2. If Z follows the standard normal distribution, find the following probabilities.
A. P(z > -1.29)
B. P(0.24 < z < 2.14)
C. P(z ≥ 1.23)
D. P(z > 5.19)
3. Monthly utility bills in a certain city are normally distributed with mean \$80
and standard deviation \$12. A random bill is selected. Find the probability it
is…
A. …between \$80 and \$115.
B. …less than \$50.
C. …more than \$95.
4. IQ scores are approximately normally distributed with mean 100 and
variance 256. If Timmy scores in the top 1% of IQ scores, what is his actual
score? What is the raw score of a person who is in the 92nd percentile of IQ
scores?
```
Related documents