Answer:
24/35 hours or 0.69 hours
Step-by-step explanation:
we know that
The speed is equal to divide the distance by the time
Let
x-----> distance traveled by John
(24-x) ----> distance traveled by Ramona
The time is equal to divide the distance by the speed
so
x/20=(24-x)/15
15x=20(24-x)
15x=480-20x
15x+20x=480
35x=480
x=480/35 miles
the time is equal to
t=x/20
t=480/(20*35)=24/35=0.69 hours
<h2>
Answer:</h2>
Variance
<h2>
Step-by-step explanation:</h2>
The standard deviation is related to the variance. The standard deviation measures the variation or dispersion of a set of data and is represented by the Greek letter sigma
, while the variance measures how far a set of numbers are spread out from their average value. The variance is obtained by squaring the standard deviation, so the variance can be found as 
Answer: The refrigerator cost in this month is $4.5 approximately.
Step-by-step explanation:
Since we have given that
Amount of watt of electric power = 320 W
Number of days = 30
Unit cost of electricity = $0.13/Kwh
Hold factor = 
Number of hours in a month = 24
So, the refrigerator cost in this month would be

Hence, the refrigerator cost in this month is $4.5 approximately.
Answer:
c
Step-by-step explanation: