SOLUTION: A student took for test in algebra improving four points on each test. Her final average was 88%. what did she make on the first test

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Question 1061174: A student took for test in algebra improving four points on each test. Her final average was 88%. what did she make on the first test
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
if the student improved 4 points on each test, than you have an arithmetic progression.

for the formula for that is An = A1 + (n-1) * d

An is the nth term whihc would be equal to 88.
A1 is the first term.
n is the number of sequences in the series.
d is the common difference which would be 4.

if she took 4 tests, then the formula would be 88 = A1 + 3*4.
solve for A1 to get A1 = 88 - 12 = 76.

the 4 terms would be 76, 80, 84, 88.

if she took 6 tests, then the formula would be 88 = A1 + 5*4.
solve for A1 to get A1 = 88 - 20 = 68.

the 6 terms would be 78, 72, 76, 80, 84, 88.