<span>Answer:
Q3 represents 75%, meaning a z of ~0.67
80 - 70 is 10, so the standard deviations is ~14.9.
10 / 0.67 = 14.9
now find the z that represents a score of 90
90 - 70 is 20
20 / 14.9 = 1.34
from a z-table, a z of 1.34 represents a probability of ~90.99% meaning that there is about a 9.01% chance of getting a 90 or better.</span>
<span>Most ancient societies had symbols to represent numbers, but they did not have symbols to represent operations or unknown quantities. Thus, the problems and solutions to the problems had to be written in word form.</span>
The total amount of money that Jeff has is $20
total fraction of his expenses on lunch and movies is:
(2/5+1/8)
=21/40
the remaining fraction is:
1-21/40
=19/40
thus the amount of cash that Jeff was left with will be:
19/40×20
=$ 9.5