# statistics

posted by .

On an exam whose scores followed a normal distribution, a student's z-score was
+2.
What percentage of students scored better than he did? (Use the 68-95-99.7 Rule.)

• statistics -

Since you are only interested in number above Z = +2, you cannot apply the rule.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion for that Z score. Multiply by 100.

## Similar Questions

1. ### statistics

for a particular sample of 77 scores on a psychology exam the following results were obtained: first quartile=44 third quartile= 71 standard deviation=6 range=45 mean= 64 median= 57 mode = 92 midrange=60 answer each of the following: …
2. ### Statistics

For a particular sample of 63 scores on a psychology exam, the following results were obtained. First quartile = 57 Third quartile = 87 Standard deviation = 9 Range = 51 Mean = 72 Median = 72 Mode = 98 Midrange = 57 Answer each of …
3. ### Statistics

For a particular sample of 63 scores on a psychology exam, the following results were obtained. First quartile = 57 Third quartile = 87 Standard deviation = 9 Range = 51 Mean = 72 Median = 72 Mode = 98 Midrange = 57 Answer each of …
4. ### statistics

For a particular sample of 63 scores on a psychology exam, the following results were obtained. First quartile = 47 Third quartile = 81 Standard deviation = 11 Range = 68 Mean = 70 Median = 71 Mode = 77 Midrange = 55 Answer each of …
5. ### Stats

For a particular sample of 63 scores on a psychology exam, the following results were obtained. First quartile = 57 Third quartile = 87 Standard deviation = 9 Range = 51 Mean = 72 Median = 72 Mode = 98 Midrange = 57 I. What score was …
6. ### statistics

For a particular sample of 80 scores on a psychology exam, the following results were obtained. First quartile = 65 Third quartile = 98 Standard deviation = 8 Range = 56 Mean = 83 Median = 81 Mode = 59 Midrange = 64 Answer each of …
7. ### math

Statistics: Analyze student exam scores Students were given an exam with 300 multiple choice questions. The distribution of the scores were normal and the mean was 195 with a standard deviation of 30. you may find it helpful to draw …
8. ### statistics

For a particular sample of 63 scores on a psychology exam, the following results were obtained. First quartile = 57 Third quartile = 72 Standard deviation = 9 Range = 52 Mean = 72 Median = 68 Mode = 70 Midrange = 57 Answer each of …
9. ### statistics

For a particular sample of 53 scores on a psychology exam, the following results were obtained. First quartile = 44 Third quartile = 68 Standard deviation = 8 Range = 55 Mean = 54 Median = 54 Mode = 71 Midrange = 64 I. What score was …
10. ### Statistics

The next three questions refer to the following situation. Data from previous years reveal that the distribution if first exam scores in an introductory statistics class is approximately normal with a mean of 72 and a standard deviation …

More Similar Questions