Let cheese wafers = x
chocolate wafers = y
we know they bought 20 total packets so x+y = 20, this can be re-written as x = 20-y
cheese wafers cost 2, so we have 2x
chocolate wafers cost 1, so we have 1y, which is just the letter y
so we know 2x + y = $25
replace x with x=20-y to get:
2(20-y)+y = 25
distribute the parenthesis:
40-2y +y = 25
combine like to terms to get:
40-y = 25
subtract 40 from each side"
-y = -15
divide both sides by -1
y = 15
chocolate wafers was y so they bought 15 chocolate wafers
cheese wafers was x, so they bought 20-15 = 5 cheese wafers
using the substitution method was the easiest way to isolate one of the variables in order to find the solution.
Answer:
The interval that represents the middle 68% of her commute times is between 33.5 and 42.5 minutes.
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
Approximately 68% of the measures are within 1 standard deviation of the mean.
Approximately 95% of the measures are within 2 standard deviations of the mean.
Approximately 99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean of 38 minutes, standard deviation of 4.5 minutes.
Determine the interval that represents the middle 68% of her commute times.
Within 1 standard deviation of the mean. So
38 - 4.5 = 33.5 minutes
38 + 4.5 = 42.5 minutes.
The interval that represents the middle 68% of her commute times is between 33.5 and 42.5 minutes.
Exponential form: F(x)= 3/125^x+1
Original voltage: 3/125 of a volt
Step-by-step explanation:
It is shifted down 2 units.
