Statistics

I'm stumped on this question.
A teacher informs her history class that a test is very difficult, but the grades would be curved. Scores for the test are normally distributed with a mean of 25 and a standard deviation of 5. If the grades are curved according to the following scheme, find the numerical limits for each grade.
A: Top 10%
B: Scores above the bottom 70% and below the top 10%
C: Scores above the bottom 30% and below the top 30%
D: Scores above the bottom 10% and below the top 70%.
F: Bottom 10%

  1. 👍 0
  2. 👎 0
  3. 👁 254
  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 and their Z scores. Insert the values into equation above to find the scores.

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. Science

    A science teacher was curious to see whether offering money for good grades would increase student performance on a test. The teacher offered half of the students in the class $5.00 if they got an A on their next test. The other

  2. Math I need help ASAP!

    1. which of the following is true of a random sample? a. it is the only way to sample a population. b. each member of the sample is a volunteer. c. it is always the easiest way to sample a population. d. each member of the

  3. English

    Five sentence paragraph. Preparing for a test should start the first day in class this includes paying attention in class,taking good notes,review all assignments on a regular basis. Budget your time make sure you set aside time

  4. science

    A science teacher tells her class that their final project requires the students to measure a specific variable and determine the velocity of a car with no more than 2.5% error. Jennifer and Johnny work hard and decide the

  1. Math

    Mr. Wong is a history teacher. In order to study how his 1st period class did on a 100-point test, he made the stem-and-leaf plot shown. Twenty-five students took the test. What conclusion can be drawn about the distribution of

  2. Science

    A science teacher was curious to see whether offering money for good grades would increase student peformance on a test. The teacher offered half of the students in the class $5.00 if they got an A on their next test. The other

  3. VERY URGENT SCIENCE

    A science teacher was curious to see whether offering money for good grades would increase student performance on a test. The teacher offered half the students in the class $5.00 if they got an A on their next test. The other half

  4. Mathematics

    Mr. Wong is a history teacher. In order to study how his 6th period class did on a 100-point test, he made the stem-and-leaf plot shown. Twenty-five students took the test. The figure shows the stem-and-leaf plot labeled as

  1. Algebra 1

    A teacher knows that 80% of her students will score no more than 5 points above or below the class average, 85%, on the test. Which inequality represents the test scores of 80% of her students? a. 75

  2. Statistics

    A science teacher gives a test with 15 questions. This teacher is a hard grader. The teacher assigns points in the following manner: a correct answer = +1 point, an incorrect answer = -1 point, no answer = 0 points. So scores on

  3. C++

    class professor {}; class teacher : public virtual professor {}; class researcher : public virtual professor {}; class myprofessor : public teacher, public researcher {}; Referring to the sample code above, if an object of class

  4. Math

    There are 24 students in Mrs.Smith's 1st block class. 1/4 of the class passed the math test with an A. 12 students in the class passed the math test with a B. What percent of the students in the class passed the test? ****** This

You can view more similar questions or ask a new question.