20 POINTS!
1 answer:
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Answer:
6
Step-by-step explanation:
The mean of a list of test scores is 80
Adding an additional test score of 92 caused the mean to rise to 82
To find:
After this additional, how many total test are in the list ?
Solution:
Let the total number of test at first =
And sum of total score =
As we know, mean =
Multiplying both sides by
Now, as adding an additional test score of 92 caused the mean to rise to 82,
By dividing both sides by minus ( - )
By dividing both sides by 2
Thus, total number of test at first = = 5
And, after this additional score added, total number of tests are
See how many times 15 can go into 120.
If 15 • 8 is 120, then the cost would have to multiply by 8.
It costs $2.00 to use the dryer for 120 minutes.
We can also use the equation to help. We plug in 120 for m and solve.
We still end up with the same result: $2.00 for 120 minutes.