What percent of 40 is 5

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

HELP COLLEGE ALGEBRA

max2010maxim [7]

Answer:

1) $\frac{-8}{11}$

2) $1.276$

3) $\frac{3}{4}$

4) $0$

Step-by-step explanation:

The slope formula of the line that pass across two points P1(x1,y1) and P2(x2,y2) is:

$\frac{y2 - y1}{x2-x1} = slope$

You can use this formula to solve all the four points:

1)

$\frac{6- -2}{-9 - 2} = \frac{-8}{11}$

2)

$\frac{- 9.1 - 0.6}{-9.5 - - 1.9} = \frac{97}{76} =(Rounded)= 1.276$

3)

$\frac{2-5}{-2 -2} = \frac{3}{4}$

4)

$\frac{4-4}{-9 --4} = \frac{0}{-5} = 0 \\\\$

3 0

3 years ago

What number is 100 less than 84 tens

Gre4nikov [31]

740, 84 x 10 - 100 = 740

8 0

3 years ago

Read 2 more answers

What’s the equation for a line passing through points (-1, 4.5) and (6, 8)?

san4es73 [151]

Answer:

Given points ( -1 , 4.5 ) and ( 6 , 8 )

Step-by-step explanation:

first we should calculate slope 

Slope ( m) 

= ( y2 - y1) / ( x2 - x1) 

= ( 8 - 4.5 ) / ( 6 + 1 )

= 3.5/7

= 0.5

Now the equation of line is given by 

y - y1 = m ( x - x1 )

y - 4.5 = 0.5 ( x + 1 )

( y - 4.5 ) = 0.5 ( x + 1)

y - 4.5 = 0.5x + 0.5

y = 0.5x + 0.5 + 4.5

y = 0.5x + 5

3 0

3 years ago

I NEED HELP WITH MATH. what is value of x?

UNO [17]

The sum of Heptagon’s inner angles is 180*(7-2)=900 degree
So x=900-146-122-142-140-110-142=98

3 0

3 years ago

What percent of 40 is 5​

What percent of 40 is 5