statics

Using the 68-95-99.7 rule:
Assume that a set of test scores is normally distributed with a mean of 100 and a standard deviation of 20. Use the 68-95-99.7 rule to find the following quantities:
Suggest you make a drawing and label first…Drawings need not be included in response.
a. Percentage of scores less than 100
b. Relative frequency of scores less than 120
c. Percentage of scores less than 140
d. Percentage of scores less than 80
e. Relative frequency of scores less than 60
f. Percentage of scores greater than 120

  1. 👍
  2. 👎
  3. 👁
  1. Make the drawing.

    a. Remember that the mean = median in a normal distribution.

    b. Since 68% score within one SD of the mean, 34% score above the mean and 34% score below. Since you are at +1 SD, add % below mean and the 34% between mean and +1 SD.

    Use a similar process for answering the remaining problems.

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. Math

    Find the mean of the data set. If necessary, round to the nearest tenth. 15.8, 14.9, 17.6, 13.4. A) 15.7 ***** B) 16.2 C) 16.7 D) 19.6 Erin wrote the following set of numbers. 37, 22, 37, 19, 34, 22, 37, 22, 32, 26, 30, 22 What is

  2. Math

    Suppose scores on an IQ test are normally distributed. If the test has a mean of 100 and a standard deviation of 10, what is the probability that a person who takes the test will score between 90 and 110?

  3. statics

    Using the 68-95-99.7rule. Assume that a set of test scores is normally distributed with a mean of 80 and a standard deviation of 25. Use the 68-95-99.7 rule to find the following quantities. percentage of scores greater than 105

  4. Statistics

    5. Scores on a recent national statistics exam were normally distributed with a mean of 80 and a standard deviation of 6. a. What is the probability that a randomly selected exam will have a score of at least 71? b. What

  1. statistics

    A test of writing ability is given to a random sample of students before and after they completed a formal writing course. The results are given below. Construct a 99% confidence interval for the mean difference between the before

  2. Statistics

    Assume that a set of test scores is normally distributed with a mean of 100 and a standard deviation of 20. Use the 68-95-99.7 rule to find the following quantities: Suggest you make a drawing and label first… a. Percentage of

  3. Math

    The scores on the GRE are normally distributed with a mean of 541 and a standard deviation of 89. Use the 68-95-99.7 rule to find the percentage of people taking the test who score between 363 and 541

  4. Math-statistics

    Assume that a set of test scores is normally distributed with a mean of 100 and a standard deviation of 20. Use the 68-95-99.7 rule to find the following quantiles: a.percentage of scores less than 100 b. relative frequency of

  1. Statistics

    The National Assessment of Educational Progress tested a simple random sample of 1000 thirteen year old students in both 2004 and 2008 and recorded each student's score. The average and standard deviation in 2004 were 257 and 39,

  2. Statistics... I need help

    . Assume that a set of test scores is normally distributed with a mean of 100 and a standard deviation of 20. Use the 68-95-99.7 rule to find the following quantities: (Hint: Make a drawing and label first) a. Percentage of scores

  3. math new question

    15. Which of the following would best display information in a frequency table that has been divided into categories? bar graph**** pictograph circle graph histogram 14. The mean of a set of four test scores is 85. If three of the

  4. Math Ms. Sue please help me

    The mean of the set of four test scores is 88. If three of the test scores are 84, 88, and 94, what is the fourth test score? A. 86 B. 88*** C. 90 D.92 please help am i right?

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