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
forsale [732]
3 years ago
13

in one region, the September energy consumption levels for single-family homes are found to be normally distributed with a mean

of 1050kWh and a standard deviation of 218 kWh. Find P45, which is the consumption level separating the bottom 45% from the top 55%
Mathematics
1 answer:
VARVARA [1.3K]3 years ago
8 0

Answer:

a=1050 -0.126*218=1022.53

So the value of height that separates the bottom 45% of data from the top 55% is 1022.53.  

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".  

Solution to the problem

Let X the random variable that represent the energy consumption of a population, and for this case we know the distribution for X is given by:

X \sim N(1050,218)  

Where \mu=1050 and \sigma=218

For this part we want to find a value a, such that we satisfy this condition:

P(X>a)=0.55   (a)

P(X   (b)

Both conditions are equivalent on this case. We can use the z score again in order to find the value a.  

As we can see on the figure attached the z value that satisfy the condition with 0.45 of the area on the left and 0.55 of the area on the right it's z=-0.126. On this case P(Z<-0.126)=0.45 and P(z>-0.126)=0.55

If we use condition (b) from previous we have this:

P(X  

P(z

But we know which value of z satisfy the previous equation so then we can do this:

z=-0.126

And if we solve for a we got

a=1050 -0.126*218=1022.53

So the value of height that separates the bottom 45% of data from the top 55% is 1022.53.  

You might be interested in
Standerd form example
slega [8]
3951 is an example of a standard form. 

What standard form means is the number is written in numerical form. 

More examples: 5269, 95862, 125634, etc. 

3 0
3 years ago
Read 2 more answers
Help me plz its about algebra 1
kkurt [141]
A

Subtract 32 from both sides first, then divide both sides by 9/5
5 0
3 years ago
How many decimals are between 0,5 and 0,6 ?
dusya [7]

Between 0.5 and 0.6 can be an infinity.

<em><u>ex:</u></em><u /><u><em /></u><em />

0.51

0.52

0.517

0.5169889549.......

0.5999999999..........

etc.

5 0
3 years ago
Read 2 more answers
How to simplify 6/35
Anestetic [448]
Well if you think about it you can evenly divide both the denominator and <span>numerator by 6. when you do this the fraction becomes 1/5.</span>
3 0
3 years ago
HELP PLZ BRAINLIEST i will give
Artist 52 [7]

Answer:

-3/2

Step-by-step explanation:

Find two points on the graph: (-1,2) and (1,-1).

Start at point (-1,2) and go down until you are at the same "x-line" as the point (1,-1). You should count 3 squares. Now, count squares to the right until you reach the point (1,-1). You should count 2. So, you have 3/2. However, the line starts from the top of the left side of the graph, so the slope is negative.

6 0
3 years ago
Other questions:
  • BIG POINTS UP FOR GRABS!!!
    15·1 answer
  • Help anyone please thanks
    10·2 answers
  • Follow the steps to solve this equation.
    6·2 answers
  • MO bisects ∠LMN, m∠NMO =6x-20,and 2x+36. Solve for x and find m∠LMO
    15·1 answer
  • The paper cup is 9 cm tall and the circular opening has a radius of 2.5 cm.
    9·1 answer
  • Pleas help person that dose it correctly gets brainiest <br><br> 10.4 x 4.8 step by step
    5·2 answers
  • Pls help<br>a9= -101 a20= 75 an=? pls help me​
    8·1 answer
  • I don’t know what to do and I need to finish this by tonight
    10·1 answer
  • It took Fred 12 hours to travel over pack ice from one town in the Arctic to another town 360 miles away. During the return jour
    7·1 answer
  • Please help meeeeeeereerreee
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!