Download Normal Distribution Name: Unit Quiz Period: Write a short paragraph

Normal Distribution
Unit Quiz
Name: ____________________________
Period: _______________________
1. Write a short paragraph addressing three things: describe a standard normal curve, what it is used for,
and how it is different from a normal curve.
2. For the z-score find the percentile rank (the % of individuals scoring below).
z = -1.65
3. For the probability given below find the z-score
99%
4. A distribution of scores has a mean of 20 and a standard deviation of 10. Find the z-scores
corresponding to the following values:
a. A score that is 20 points below the mean.
z =_____
b. A score when the x is 35.
z =_____
c.
z =_____
A score that is 15 points above the mean.
Normal Distribution
Unit Quiz
Name: ____________________________
Period: _______________________
5. For a normal curve: N(20,3), Show on the graph the area of the middle 68% of the data and write in the
values at the boundaries.
6. What is the probability that a value picked at random from the standard normal distribution
will be between -1.96 and 1.96?
7. Use N(2000,100). Draw a quick sketch showing each situation and solve.
a. What percent of the data points are under 1900?
b. What percent of the data points are between 1800 and 2200
Normal Distribution
Unit Quiz
Name: ____________________________
Period: _______________________
The heights of 800 athletes are modeled by a normal distribution with mean 180 cm and standard deviation
5.2 cm. Draw a sketch for each problem and solve.
8. What is the height of someone at the 75th percentile?
9. What is the height of someone in the top 5 percent?
10. How many students are shorter than 170 cm?
11. Bob has a z-score of 1.71 on the achievement test. The test scores were normally distributed with an
average of 1300 and a standard deviation of 150.
a) Did he score higher than John’s score which was at the 97th percentile?
b) What was Bob's score?
12. Mensa is the largest high-IQ society in the world. Mensa accepts SAT and IQ scores as indications of
intelligence. Assume that the mean combined SAT score is 1450, with standard deviation 290. Jacinto
scored a combined 2070. Maria took a traditional IQ test and scored 127. On that test, the mean is 100
and the standard deviation is 16. From the test scores, who is more intelligent? Explain.
13. What is the standard deviation if the mean = 1250 and 35% of the data points are below 1200?
Normal Distribution
Unit Quiz
Begin the Excel Portion of the test
Name: ____________________________
Period: _______________________