What z score in a normal distribution has 33% of all score above it?
Answer: A z score which has 33% of all scores above it, will have 67% of all scores below it.
To find the required z score, we need to find the z value corresponding to probability 0.67.
Using the standard normal table, we have:
Therefore, the z score = 0.44 has 33% of all score above it.
Answer
Find out the which system of equations could be used to determine the number of hours charged at the day rate (d) and at the night rate (n) .
To proof
As given in the question
Let us assume that the number of hours charged at the day rate = d
Let us assume that the number of hours charged at the night rate = n
An online data base charges $25 an hour during the day and $12.50 an hour at night. If a research company paid $250 for 12 hours of use.
Total working hour in a company including day and night be 12 hours .
than the equation become in the form
d + n = 12
also
An online data base charges $25 an hour during the day
$12.50 an hour at night.
If a research company paid $250 for 12 hours of use.
than the equation becomes
25d + 12.50n = 250
than the two equation are
d + n = 12 , 25d + 12.50n = 250
multiply first by 25 and subtracted from 25d + 12.50n = 250
25d - 25d + 12.50n - 25n = 250 - 300
12.5 n = 50
n = 4hours
put this in the d + n = 12
d + 4 =12
d = 12-4
d = 8 hours
Therefore the number of hours charged at the day rate is 8 hours and at the night rate is 4hours .
Hence proved
