A score of 85 would be 1 standard deviation from the mean, 74. Using the 68-95-99.7 rule, we know that 68% of normally distributed data falls within 1 standard deviation of the mean. This means that 100%-68% = 32% of the data is either higher or lower. 32/2 = 16% of the data will be higher than 1 standard deviation from the mean and 16% of the data will be lower than 1 standard deviation from the mean. This means that 16% of the graduating seniors should have a score above 85%.
<span>Lois used a credit card to make the purchase.
One can't purchase an item that costs more than the balance in a debit card. The debit card is equivalent to cash on hand. You can only spend what you have.
The credit card is equivalent to a loan. You don't have the money as of the moment but when you use the credit card, you owe the issuing bank the amount you've put on credit. The bank will pay the merchant and you will pay the bank. Interest is an additional expense when you pay your bill beyond the due date. The interest is applied on the amount outstanding upon the payment due date. </span>
If you would like to solve the system of equations 5x + 4y = 12 and 3x - 3y = 18 using elimination, you can do this using the following steps:
<span>5x + 4y = 12 /*3
3x - 3y = 18 /*4
_____________
15x + 12y = 36
12x - 12y = 72
_____________
15x + 12y + 12x - 12y = 36 + 72
15x + 12x = 36 + 72
27x = 108
x = 108/27
x = 4
</span><span>3x - 3y = 18
</span>3 * 4 - 3y = 18
12 - 3y = 18
12 - 18 = 3y
3y = -6
y = -6/3
y = -2
(x, y) = (4, -2)
The correct result would be: x = 4 and y = -2.
I'm going to assume you meant to write fractions (because if 
are all non-negative integers, the series would clearly diverge), so that
and so on.
a. If the pattern continues as above, we would have the general term
b. Note that we can write as
The series diverges by comparison to the divergent series
If you're asking about what the equation would be written as, then it's y = 1x + 1,400.
