For a hypothetical normal distribution of test scores, approximately 95% fall between 38 and 62, 2.5% are below 38, and 2.5% are above 62. Given this information, (a) the mode=_____ and (b) the standard deviation=_____

Thanks in advance!

  1. 👍 0
  2. 👎 0
  3. 👁 342
  1. To find the mean (this is also the mode):
    (38 + 62)/2 = 50

    95% equals 2 standard deviations about the mean. Therefore, to find 1 standard deviation:
    (50 - 38)/2 = 6
    (62 - 50)/2 = 6

    I hope this helps.

    1. 👍 0
    2. 👎 0
  2. Thank you very much! I am having real problems with that. Is that the formula that should be used:

    ơ=√∑ (x- µ)2/N


    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. statistics

    A consumer group wants to know if an automobile insurance company with thousands of customers has an average insurance payout for all their customers that is greater than $500 per insurance claim. They know that most customers

    asked by Anonymous on April 6, 2020
  2. statistics

    Scores on a test have a mean of 66 and Q3 of 81. The scores have a distribution that is approximately normal. Find the standard deviation. Round your answer to the nearest tenth.

    asked by Abby on March 29, 2010
  3. stats

    Which of the following can be reasonably modeled by a normal distribution? The favorite colors of students in a kindergarten class A The heights of tomato plants that were all planted on the same day B The percent of employees

    asked by Anonymous on September 30, 2019
  4. 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

    asked by Leozap on May 1, 2015
  5. statistics

    Answer the question(s) based on the following situation: 150 students in a math class take the final exam. The scores on the exam have an approximately normal distribution with center ì = 65 and standard deviation ó = 10.The

    asked by Whitney on March 17, 2010
  1. college

    1. Which of the following statements are correct? a. A normal distribution is any distribution that is not unusual. b. The graph of a normal distribution is bell-shaped. c. If a population has a normal distribution, the mean and

    asked by Jay on August 1, 2010
  2. Statistics

    Suppose that two different tests A and B are to be given to a student chosen at random from a certain population. Suppose also that the mean score on test A is 85, and the standard deviation is 10; the mean score on test B is 90,

    asked by Charles on February 16, 2011
  3. statistics

    10th grade New York public school students taking a standardized English test produced test scores that were normally distributed with a mean of 85 and a standard deviation of 4. Let x be a random variable that represents the test

    asked by jill on December 4, 2016
  4. statistics

    Given a normal distribution of scores with a mean of 100 and a SD of 10, compute z scores for the following raw valves: 95, 115, 80, 130.

    asked by Anonymous on November 13, 2011
  5. statistics

    The respiratory rate per minute in newborns varies according to a distribution that is approximately Normal with mean 50 and standard deviation 5. The proportion of observations from a standard Normal distribution that take values

    asked by Jen on July 9, 2013
  6. Statistics

    Mrs. Marble gave her 5th grade class a math test. The scores reflect a relatively normal distribution. The mean score for the group was 80 with a standard deviation of 8. Based upon this information, answer the following

    asked by Susana on January 27, 2013

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