Math

posted by .

Consider the following test scores obtained by a class.



Test score 90 80 70 60 50
Frequency 1 4 11 6 2

Find the standard deviation (rounded to the nearest hundredth).
--------------------------------
I've posted this question earlier and I'm still getting the wrong answer.
I don't know from what point I messed up.....

this is what I did.
Mean:
90+320+770+360+100 / 24 = 68.33

Deviation
469.59+136.19+2.79+69.39+335.99 / 24= 42.25

then square root of 42.45 is 6.5

but my answer came wrong. please help!
I can't move on to my next homework question because I keep getting this wrong :(

  • Math -

    Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.

    For example, with the score of 80:

    (80-68.33)^2 * 4 = 136.19 * 4 = ?

    Do this with all the frequencies.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. statistics

    a math test has a mean of 43 and a standard deviation of 17.0. find the corrresponding z scores for a test score of 13 and a test score of 59. show work
  2. statistics

    a math test has a mean of 43 and a standard deviation of 17.0. find the corresponding z scores for a test score of 13 and a test score of 59. show all work.
  3. college, statistics

    a math test has a mean of 43 and a standard deviation 0f 17.0. find the corresponding z scores for. show all work. I. a test score of 13 II. a test score of 59
  4. Stats

    A Math test has a mean of 51 and standard deviation of 5.0. Find the corresponding z scores for: I. a test score of 64 II. a test score of 47
  5. 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 …
  6. Math

    Consider the following test scores obtained by a class. Test score 90 80 70 60 50 Frequency 1 4 11 6 2 Find the standard deviation (rounded to the nearest hundredth).
  7. ALGBRA

    Consider the following test scores obtained by a class. Test score 90 80 70 60 50 Frequency 1 4 11 6 2 Find the standard deviation (rounded to the nearest hundredth). -------------------------------- I've posted this question earlier …
  8. statistics

    1. Suppose you administered an anxiety test to a large sample of people and obtained normally distributed scores with a mean of 45 and a standard deviation of 4. Do not use the web calculator to answer the following questions. Instead, …
  9. Math

    1. Gerald received the following test scores in math class: 76, 86, 89, 81, and 99. What was Gerald’s average test score, rounded to the nearest point?
  10. math

    What is the standard deviation of the following test scores?

More Similar Questions