Math

if there are 145 test questions, and the mean of the test scores for a class is 100 with a standard devation of 15, what percentage of the people taking the test would have the following scores: scored b/w 100 &115, scored b/w 100 & 115,scored b/w 0 & 100, scored b/w 0 & 145, or scored b/w 0 &85?

  1. 👍 0
  2. 👎 0
  3. 👁 41
  1. Z = (score-mean)/SD

    Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores.

    1. 👍 0
    2. 👎 0
    posted by PsyDAG

Respond to this Question

First Name

Your Response

Similar Questions

  1. algebra

    Mrs. Gifford's class consists of 15 girls and 25 boys.On the first test the mean of the girls’ scores was 80 and the mean of the boy’s scores was 70. What was the class mean? (Remember the class mean is not just averaging the

    asked by Anonymous on December 19, 2018
  2. Alegbra 1

    Mrs. Gifford's class consists of 15 girls and 25 boys. On the first test the mean of the girls’ scores was 80 and the mean of the boy’s scores was 70. What was the class mean? (Remember the class mean is not just

    asked by Bill on December 15, 2017
  3. Math - Averages

    The test average for Louis' calculus class is found by taking the arithmetic mean of his four best test scores. If his first four test scores are 65,82,76 and 87, what score must he get on the fifth test to raise his test average

    asked by Venus on September 13, 2013
  4. Alegbra 1

    On the first test the mean of the girls’ scores was 80 and the mean of the boy’s scores was 70. What was the class mean? (Remember the class mean is not just averaging the two means) On the second test, the class

    asked by Bill on December 15, 2017
  5. maths

    What is mode n average for 2 students test scores our of 25 for maths. A Test 1: =21 Test 2: =24 Test 3:=19 Test 4: =21 K Test 1:= 18 Test 2:= 19 Test 3:= 19 Test 4:= 17 Test 2:= 19 Test 3:= 19 Test 4:= 17. N Test 1:= 16 Test 2:=

    asked by nyle wilkes on November 28, 2016
  6. Algebra

    Your test scores in one class are 8484 and 88. What possible scores can you earn on your next test to have a test average between 86 and 90​, ​inclusive

    asked by Benjamin on September 16, 2016
  7. Algebra

    Your test scores in one class are 85 and 88. What possible scores can you earn on your nest test to have a test average between 86 and 90, inclusive?

    asked by Eden on October 20, 2015
  8. Statistics

    Suppose you gave a skill test to 3 different PE classes and want to know if they differ in terms of their scores. The skill tests scores are as follows: Class 1: 23, 21, 19, 22 Class 2: 18, 19, 21, 18 Class 3: 21, 20, 19, 22

    asked by Lisa on December 13, 2011
  9. statistics

    below is the test scores for students in a statistics class.80,65,79,83,60,79,90,77,84,93.the professor assigned a grade of c to students whose test scores were within 5 points of the mean in either direction .how many students

    asked by ron on October 4, 2011
  10. Math

    A teacher gives a test to a class of 20 student. Is it possible that 90% of the class scores above average? Give examples of test scores for which this is the case. If not, explain why not?

    asked by Uknown on April 13, 2017

More Similar Questions