The sum of all the measurements is just the average times the number.


So if the average of all 92 is 7 the sum of those is

The average of the last two is 7.2 so their sum is

That means the sum of the first 90 is

so the average of the first 90 is

cm
It’s c) XS, i love your pfp btw!! :)
The one year-plan would have a credit, so it would have a positive sign. In the monthly plan, there is a high risk of being late in paying the bills. That's why a fine of $10 is given for every month that you are late. If you are not time conscious and you end up being late every month, it would give you a negative balance.
The number of dimes is 75 coins.
The number of nickels is 1 coin.
<u>Step-by-step explanation:</u>
It is given that,
A box contains 76 coins, only dimes and nickels.
- The 10 cent coin is called a dime.
- Let, the number of dimes be x.
- The 5 cent coin is called a nickel.
- Let, the number of nickels be y.
<u>This is represented by the system of equations :</u>
x + y = 76 -------(1)
10x + 5y = 4.90 ------(2)
Multiply eq (1) by 5 and subtract eq (2) from eq (1),
5x + 5y = 380
-<u>(10x + 5y = 4.90)</u>
<u>-5x = 375.1</u>
x = 375/5
x = 75 coins.
The number of dimes is 75 coins.
Substitute x=75 in eq (1),
y = 76 - 75
y = 1 coin.
The number of nickels is 1 coin.