Answer:
She needs a grade of 71 on her next text.
Step-by-step explanation:
Mean of a data-set:
The mean of a data-set is the sum of all values in the data-set divided by the number of values.
Tammy has scored 82, 78, and 93 on her previous three tests.
Thus, her grades are 82, 78, 93 and x, in which x is her grade in the fourth test.
There are 4 tests.
What score does she need on her next test so that her average (mean) is 81?
We have to find x when the mean is 81. So
She needs a grade of 71 on her next text.
Answer:
Carlos and Pamela drove 120 miles on the first day, 240 miles on the second day, and 290 miles on the third day.
Step-by-step explanation:
Let x be the number of miles driven on the first day.
Then they drove twice as many miles, or 2x on the second day
and 50 miles more than the second day's, so 2x + 50
The total is 650 across all three days, so we'll take the sum.
x + 2x + (2x + 50) = 650
Combine like terms on the left
5x + 50 = 650
Subtract 50 on both sides
5x = 600
Divide by 5 on both sides
x = 120
Check work:
120 + 2(120) + 2(120) + 50 = 650
120 + 240 + 240 + 50 = 650
600 + 50 = 650
650 = 650
So they drove 120 miles on the first day
2*120 = 240 miles on the second day
and 2*120 + 50 = 240 + 50 = 290 miles on the third day
Answer:
2
Step-by-step explanation:
