Suppose that prices of a gallon of milk at various stores in one town have a mean of $3.91 with a standard deviation of $0.13. Using Chebyshev's Theorem, what is the minimum percentage of stores that sell a gallon of milk for between $3.65 and $4.17

The minimum percentage of stores that sell a gallon of milk for between $3.65 and $4.17 is of 75%.

Step-by-step explanation:

Chebyshev Theorem

The Chebyshev Theorem can also be applied to non-normal distribution. It states that:

At least 75% of the measures are within 2 standard deviations of the mean.

At least 89% of the measures are within 3 standard deviations of the mean.

An in general terms, the percentage of measures within k standard deviations of the mean is given by .

In this question:

We have a mean of $3.91 and a standard deviation of $0.13.

Using Chebyshev's Theorem, what is the minimum percentage of stores that sell a gallon of milk for between $3.65 and $4.17?

3.65 = 3.91 - 2*0.13

4.17 = 3.91 + 2*0.13

Within 2 standard deviations of the mean, so, by the Chebyshev's Theorem, the minimum percentage of stores that sell a gallon of milk for between $3.65 and $4.17 is of 75%.

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18