After four tests Trudy's average score was 85. If her score is 90 on the fifth test, what will be her average for all five tests?

2 Answers
Tony B
May 8, 2018

Average (mean ) = 86#

Explanation:

Note that there are 3 different types of average. I am assuming you wish to use the mean value.

If you add up all the first 4 test scores you would have:
#4xx85= 340#

If we now include the 5th score we have a total of #340+90 = 430#

So the new 'mean' is #430/5 = 86#

Jim G.
May 8, 2018

#86#

Explanation:

#• " average "="total score"/"count"#

#"that is "85="total score"/4#

#"multiply both sides by 4"#

#rArr"total score "=4xx85=340#

#"total score after fifth test "=340+90=430#

#rArr"average "=430/5=86#

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