1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Oksana_A [137]
3 years ago
9

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

ned. Assume a population standard deviation of 450 kilowatt-hours. If the sample mean is 1858 kWh, the 95% confidence interval estimate of the population mean is
Mathematics
1 answer:
lana [24]3 years ago
6 0

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)

You might be interested in
I rlly need help with this gr 11 math problem
prohojiy [21]

Answer:

a) \frac{d-5.50}{0.45}

b) The inverse function is a reflection of the original function across the line

y = x. For example, if the function f applied to an input x gives a result of y, then applying its inverse function g to y gives the result x. So you would use it to find the x-value at a y just like you use the original to find the y value at an x.

Step-by-step explanation:

To do an inverse of a function you first switch the independent variable (d) and the dependent variable (c).

d = 0.45c + 5.50

Then you solve for c

d - 5.50 = 0.45 c

c = (d-5.50)/0.45

8 0
3 years ago
Find the sum: (2x^2 + x + 3) + (3x^2 + 2x + 1)
Montano1993 [528]

Answer:

5x^2 +  3x   +4

Step-by-step explanation:

(2x^2 + x + 3) + (3x^2 + 2x + 1)

Combine like terms

(2x^2 + 3x^2 + 2x+ x + 3 + 1)

5x^2 +  3x   +4

6 0
3 years ago
The table shows the number of cups of water required when cooking different amounts of rice.
Harman [31]

<u>Answer-</u>

<em>The amount of water is the dependent value.</em>

<u>Solution-</u>

Plotting the graph from the given data points, it comes out to be a straight line with positive slope. So, both the variables i.e amount of rice and amount of water are in a linear relationship. They are directly proportional to each other.

As the amount of rice increases, the water needed to cook the rice also increases. Plotting a graph taking amount of rice in abscissa and amount of water in ordinate, a straight line was obtained.

Here, amount of rice is the independent variable and amount of water is dependent variable as it depends on the amount of rice.

3 0
3 years ago
Write the phrase "one more than the product of six and nine" as a mathematical expression.
frosja888 [35]

Answer:

<em>C. 6 ⋅ 9 + 1 </em>

Step-by-step explanation:

Start with the multiplication:

"one more than the product of six and nine"

6 ⋅ 9

Now take care of the addition by adding 1 to the product.

"one more than the product of six and nine"

6 ⋅ 9 + 1

Answer: C. 6 ⋅ 9 + 1

4 0
3 years ago
Aaron was offered a job that paid a salary of \$57,000$57,000 in its first year. The salary was set to increase by 1% per year e
Jobisdone [24]

Answer:

The total amount received is: $1906650

Step-by-step explanation:

Given

a = \$57000 --- initial

b = 1\% --- rate

n = 29 --- time

Required

Determine the total amount at the end of 29 years

The given question is an illustration of geometric progression, and we are to solve for the sum of the first n terms

Where n = 29

r = 1 + b

r = 1 + 1\%

Express percentage as decimal

r = 1 + 0.01

r = 1.01

The required is the calculated using:

S_n = \frac{a(r^n - 1)}{r - 1}

So, we have:

S_n = \frac{57000 * (1.01^{29} - 1)}{1.01 - 1}

S_n = \frac{57000 * (1.3345- 1)}{0.01}

S_n = \frac{57000 * 0.3345}{0.01}

S_n = \frac{19066.5}{0.01}

S_n = 1906650

<em>The total amount received is: $1906650</em>

8 0
3 years ago
Other questions:
  • Write the equation of a line perpendicular to 3x+2y=6 through (2,-1).
    8·1 answer
  • Sherri hikes on the Pacific Coast trail. She plans to hike 3.72 miles. If she hikes at an average speed of 1.2 miles per hour, h
    9·1 answer
  • To win a game, Francine needs to move more than 10 spaces
    9·1 answer
  • The slope of y=13/12x+43
    14·1 answer
  • Need Help
    5·2 answers
  • Can someone tell me the answer I’ll give u 29 pints
    10·2 answers
  • What is the slope of a line that is parallel to the line represented by the equation y=7/6x+4
    11·1 answer
  • PLEASE ANSWER CORRECTLY:
    14·1 answer
  • I cant get this at all
    11·1 answer
  • 4-6 study guide and intervention isosceles and equilateral triangles
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!