(-y+5x3)+(7.2y-9)=6.2y+n
(-y+15)+(7.2y-9)=6.2y+n
since you're adding the two parentheses, you don't need to have them there
-y+15+7.2y-9=6.2y+n
7.2y-y +15-9 =6.2y+n
6.2y + 6 =6.2y+n
6.2y - 6.2y -n = -6
-n=-6
n=6

3 0

3 years ago

In order to estimate the average electric usage per month, a sample of 81 houses was selected and the electric usage was determi

lana [24]

Answer:

Confidence interval: (1760,1956)

Step-by-step explanation:

We are given the following information in the question:

Sample size, n = 81

Sample mean =

$\bar{x} = 1858 \text{ kWh}$

Population standard deviation =

$\sigma = 450 \text{ kilowatt-hours}$

Confidence Level = 95%

Significance level = 5% = 0.05

Confidence interval:

$\bar{x} \pm z_{critical}\displaystyle\frac{\sigma}{\sqrt{n}}$

Putting the values, we get,

$z_{critical}\text{ at}~\alpha_{0.05} = \pm 1.96$

$1858 \pm 1.96(\displaystyle\frac{450}{\sqrt{81}} ) = 1858 \pm 98 = (1760,1956)$

6 0

3 years ago

At summer camp, campers were asked to name their favorite sport. The circle graph shows the percent of campers who preferred eac

vladimir1956 [14]

I would say 260

Hope I helped

5 0

3 years ago

Read 2 more answers

Using fraction bar to find sum for 1/3 1/3 1/6

PIT_PIT [208]

1/3 1/3 1/6= 1+1=2/6 1/6=3/6 simply it to 1/2

8 0

3 years ago

Read 2 more answers