In order to estimate the difference between the average hourly wages of employees of two branches of a department store, the following data have been gathered.

downtown store north mall store
sample size 25 20
sample mean $9 $8
sample standard deviation $2 $1
a 95% interval estimate for the difference between the two population means is

1.09 to 4.08

0.07 to 1.9

1.08 to 2.92

1.9 to 2.08

0.07 to 1.9

Step-by-step explanation:

Let and be the population mean of hourly wages of employees of two branches of a department store (Downtown Store and  North Mall Store)

As per given , we have

Degree of freedom :

Critical value for 95% confidence interval :

Then, 95% interval estimate for the difference between the two population means will be

Hence, A 95% interval estimate for the difference between the two population means is .

i.e. 0.07 to 1.9

a) y = -3x +2

b) y = 1/2x -6

these 2 can be combined into one equation.

-3x +2 = .5x -6

8 = 3.5x

x = 8 / 3.5 = 2.2857142857

y = -3 * (8 / 3.5) +2

y = (-24 / 3.5) + 2

y = -4.8571428571

step-by-step explanation:

the formula of a slope:

we have the points (-2, 7) and (2, 3). substitute: