An arithmetic student needs an average of 70 or more to receive credit for the course. She scored 84, 66, and 93 on the first three exams. Write an inequality representing the score she must get on the last test to receive credit for the course.
2007-08-12 14:40:38 · 22 answers · asked by ray 1 in Science & Mathematics ➔ Mathematics
(a_1 + a_2 + a_3 + ....a_n)/n >= 70
2007-08-12 14:46:02 · answer #1 · answered by Anonymous · 0⤊ 1⤋
Let x be the lowest score she must get to get credit
then
average of 4 test = (84 + 66 + 93 + x)/4
the student neesds
(84 + 66 + 93 + x)/4 >= 70
(243 + x)/4 >= 70
243 +x >= 280
or
x >= 280 - 243 = 37
The students needs a score of 37 or bettter on the 4th test.
2007-08-12 21:47:47 · answer #2 · answered by vlee1225 6 · 1⤊ 1⤋
X = amount needed for last exam
70*4 ⤠84+66+93+X
280 ⤠243+X
37â¤X
She must score a 37 or higher
2007-08-12 21:47:53 · answer #3 · answered by Masaki 367 2 · 1⤊ 1⤋
To pass the test she must have 4 exams average to 70 or more. This means that their total must be 280 or more.
The total so far is 84+66+93= 243
The difference is 47.
Final exam score must = or > 47
2007-08-12 21:42:49 · answer #4 · answered by ignoramus 7 · 2⤊ 0⤋
[(84 + 66 + 93 + x) / 4] mustr be greater than or equal to 70. x = 37.
2007-08-12 21:46:49 · answer #5 · answered by Anonymous · 1⤊ 0⤋
84+66+93+X / 4 > or = 70
answer is 35
2007-08-12 21:47:35 · answer #6 · answered by cowpony 3 · 0⤊ 1⤋
(84+66+93+x)/4 must be greater than or equal to 70
2007-08-12 21:46:08 · answer #7 · answered by Krystle K 1 · 0⤊ 1⤋
70x4=280
84+66+93=243
Average right now with three tests is: 81
280-243=37.
The student will need a score of 37 to pass.
2007-08-12 21:58:35 · answer #8 · answered by lady_bella 6 · 0⤊ 0⤋
84*66*93*n/4=70
2007-08-12 21:48:55 · answer #9 · answered by [♥that girl♥] 4 · 0⤊ 1⤋
(84 + 66 + 93 + x)/4 >/= 70
That is greater than or equal to, but I don't have that as a key.
You really couldn't get this? I hope you're in seventh grade.
2007-08-12 21:48:10 · answer #10 · answered by Deedee 1 · 0⤊ 1⤋
61
2007-08-12 21:47:11 · answer #11 · answered by budda 3 · 0⤊ 1⤋