Current balance - 12 months a year times the monthly fee
=75-12(12.50)
=75-150
=-75
She will have negative $75 so she will be below zero.
Answer: 5 units
Step-by-step explanation:
The area of a parallelogram is
. SInce we know the area and the height, we can directly plug the values into this equation and solve for the base.
20=b(4) [divide both sides by 4]
b=5 units
Let
be the random variable for the number of marks a given student receives on the exam.
10% of students obtain more than 75 marks, so

where
follows a standard normal distribution. The critical value for an upper-tail probability of 10% is

where
denotes the CDF of
, and
denotes the inverse CDF. We have

Similarly, because 20% of students obtain less than 40 marks, we have

so that

Then
are such that


and we find

c. 4.6
21 X .22= 4.6
Calculating the variance requires finding the product of 21 and 22%. To make this easier we convert 22% into it's decimal form and construct the equation. To back check this answer we can use 10% of 21 voters which equals 2.1% then double that amount to reach 4.2%, knowing that we now have a close approximation of the variance we can eliminate answers a, b, and d, leaving c as the only logical choice.