Answer to Question #173734 in Statistics and Probability for Rustom

Question

Before you proceed and explore more about the normal curve, let us see how

much you know before we tackle the lesson. Determine whether each of the following 

statements is true or false. Write T if the statement is correct and write F if not.

1. Percentile rank is the percent of cases that are at or below a score.

2. 90thpercentile means that 90% of the grades were higher than yours and

10% were lower.

3. The 90th percentile under the normal curve is z = 1.28.

4. The upper 5% of the normal curve is above z = 0.56.

5. The 95th percentile under the normal curve is 𝑧 = 1.60

Answer 1

1. Percentile rank is the percent of cases that are at or below a score.

T

2. 90th percentile means that 90% of the grades were higher than yours and

10% were lower.

F

(Percentiles indicate the percentage of scores that fall below a particular value.)

3. The 90th percentile under the normal curve is z = 1.28.

T

4. The upper 5% of the normal curve is above z = 0.56.

F

(The upper 5% of the normal curve is above z = 1.645.)

5. The 95th percentile under the normal curve is 𝑧 = 1.60

F

(The 95th percentile under the normal curve is z = 1.645.)