Answer: 72.78% of the drivers are traveling between 70 and 80 miles per hour based on this distribution.
Step-by-step explanation:
Let X be a random variable that represents the speed of the drivers.
Given: population mean : M = 72 miles ,
Standard deviation: s= 3.2 miles
The probability that the drivers are traveling between 70 and 80 miles per hour based on this distribution:
Hence, 72.78% of the drivers are traveling between 70 and 80 miles per hour based on this distribution.
You must drive more than 40 miles to make option A the cheaper plan
<em><u>Solution:</u></em>
Two payment options to rent a car
Let "x" be the number of miles driven in one day
<em><u>You can pay $20 a day plus 25¢ a mile (Option A)</u></em>
25 cents is equal to 0.25 dollars
OPTION A : 20 + 0.25x
<em><u>You pay $10 a day plus 50¢ a mile (Option B)</u></em>
50 cents equal to 0.50 dollars
Option B: 10 + 0.50x
<em><u>For what amount of daily miles will option A be the cheaper plan ?</u></em>
For option A to be cheaper, Option A must be less than option B
Option A < Option B
Solve the inequality
Add -0.50x on both sides
Add - 20 on both sides,
Divide both sides by 0.25
Thus you must drive more than 40 miles to make option A the cheaper plan