Posted by Joe on Sunday, March 8, 2009 at 11:42am.
Sally took four tests in science class. On each successive test, her score improved by 3 points. If her mean score was 69.5%, what did she score on the first test?

college algebra  Hannah Xx, Sunday, March 8, 2009 at 11:47am
66.5%

college algebra  Joe, Sunday, March 8, 2009 at 12:08pm
thanks for the answer but can you please show how you got that answer

college algebra  mark, Sunday, March 8, 2009 at 12:36pm
the tests improve by 3 points, therefore:
test 1 x
test 2 x+3
test 3 x+6
test 4 x+9
the mean is the sum of the test scores divided by the number of tests. also, we know the mean = 69.5%
therefore, we get the equation:
(4x+18)/4 = 69.5%
4x+18 = 278
4x = 260
x = 65
therefore the score on the first test was 65%
Answer This Question
Related Questions
 social science statistics  a professor was curious to whether the students in a...
 algebra  Briana's second test score was 8 points higher than her first score. ...
 graduate statistics  A nursing professor was curious as to whether the students...
 math  Adam took five tests and received a grade for each of them. The first ...
 algebra  Jacob has a mean score of 78 after his first four math tests. He wants...
 math  A teacher allows the students to each "throw out" their lowest test score...
 Algebra  Tom took five math tests and got an integer score on each of them. He ...
 Algebra  Tom took five math tests and got an integer score on each of them. He ...
 Math  Karl's scores on the first five science tests are shown in the table. ...
 algebra  sasha needs to score at least 360 points on 4 tests to earn an A. on ...
More Related Questions