# algebra 2 and trig

posted by caroline

The scores on a chemistry test are normally distributed. Approximately 95 percent of the scores fell between 78 and 92. What is the standard deviation for this distribution?

1. Steve

how many std's away is the 2.5% boundary?
The mean is at (78+92)/2 = 85

## Similar Questions

1. ### Word Problem

A math teacher gives two different tests to measure students' aptitude for math. Scores on the first test are normally distributed with a mean of 25 and a standard deviation of 4.6. Scores on the second test are normally distributed …
2. ### Statistics

A distribution of 800 test scores in a biology course was approximately normally distributed with a mean of 35 and a standard deviation of 6. Calculate the proportion of scores falling between 20 and 40
3. ### Statistics Math Help

A distribution of 800 test scores in a biology course was approximately normally distributed with a mean of 35 and a standard deviation of 6. Calculate the proportion of scores falling between 20 and 40
4. ### 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 …
5. ### STATISTICS

Scores on the LSAT are approximately normally distributed. In fact, published reports indicate that approximately 40 percent of all test takers score at or between 145 and 155, and about 70 percent score at or between 140 and 160. …
6. ### stats.

The GMAT test is required for admission to most graduate programs in business. In a recent year, the GMAT test scores were normally distributed with a mean of 550 and standard deviation of 100. A. Find the first quartile for the distribution …
7. ### Algebra

Scores on a test have a mean of 66 and Q3 is 80. The scores have a distribution that is approximately normal. Find the standard deviation. Round your answer to the nearest tenth. 10.5 18.7 20.9 9.4
8. ### Algebra

I do not understand this homework at all. Any help or elaboration would be greatly appreciated. Thanks. 100 juniors at Southwest High took the SAT test. The scores were distributed normally with a mean of 22 and a standard deviation …
9. ### Math

Scores on the LSAT are approximately normally distributed. In fact, published reports indicate that approximately 40 percent of all test takers score at or between 145 and 155, and about 70 percent score at or between 140 and 160. …
10. ### Math

Scores on the LSAT are approximately normally distributed. In fact, published reports indicate that approximately 40 percent of all test takers score at or between 145 and 155, and about 70 percent score at or between 140 and 160. …

More Similar Questions