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
lord [1]
3 years ago
13

Assume that blood pressure readings are normally distributed with μ = 122 and σ = 7.5. A researcher wishes to select people for

a study but wants to exclude the top and bottom 10 percent. What would be the upper and lower readings to qualify people to participate in the study?
Mathematics
1 answer:
harina [27]3 years ago
4 0

Answer:

z=-1.28

And if we solve for a we got

a=122 -1.28*7.5=112.4

So the value of height that separates the bottom 10% of data from the top 90% is 112.4.  

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 blood pressures of a population, and for this case we know the distribution for X is given by:

X \sim N(122,7.5)  

Where \mu=122 and \sigma=7.5

And the best way to solve this problem is using the normal standard distribution and the z score given by:

z=\frac{x-\mu}{\sigma}

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

P(X   (a)

P(X>a) =0.9   (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 01 of the area on the left and 0.90 of the area on the right it's z=-11.28. On this case P(Z<-1.28)=0.10 and P(z>-1.28)=0.9

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

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=-1.28

And if we solve for a we got

a=122 -1.28*7.5=112.4

So the value of height that separates the bottom 10% of data from the top 90% is 112.4.  

You might be interested in
Eight women and six men apply for a job at Google. Four of the applicants are selected for interviews. Let X denote the number o
Free_Kalibri [48]

Answer:

See below

Step-by-step explanation:

images attached showing all working

a) The possible values of X are as follows

X = {0,1,2,3,4}

P(x) = P(X=x)

b) The cdf in this case, as in the F(x), comes out to be a step function graph on the basis of values obtained from the probability mass function.

c) To find out the probability when more women are interviewed than me, add together the matrices from when value of X is equal to 2, 3 and 4 (from part a).

7 0
3 years ago
Can someone please help me with this algebra
Novay_Z [31]

Answer: d

Step-by-step explanation:

5 0
2 years ago
Read 2 more answers
Do the math please. i need it nowwwwww
denis-greek [22]

Using algebraic expressions, the value of x in the diagram given is calculated as: x = 4

<h3>What is an Algebraic Equation?</h3>

An algebraic equation is an equation that has an unknown variable (i.e. x) and digits, which can be used to solve a problem.

Algebraic expression for Mat A is: 4x + 3

Algebraic expression for Mat B is: 2x + 11

We would have the following algebraic equation:

4x + 3 = 2x = 11

Solve for the value of x

4x - 2x = 11 - 3

2x = 8

x = 8/2

x = 4

Learn more about algebraic equations on:

brainly.com/question/2164351

#SPJ1

6 0
2 years ago
How are quadratic equations different from linear equations?
worty [1.4K]
The fundamental difference between the linear and quadratic functions is observed in their respective graphs. A linear function is represented by a straight line and a quadratic function is represented by a curve called a parabola.

See file attached.


3 0
3 years ago
Help please this is urgent
Licemer1 [7]
25a-5a


Hope this helps!!!!
8 0
3 years ago
Read 2 more answers
Other questions:
  • SOMEONE HELP ME QUICK PLEASE PLEASE
    11·1 answer
  • becky is rolling a number cube with the numbers 1 through 6 what is the probability she will roll 4 or 5
    10·1 answer
  • the original cost of a piano is 19,100 and it is on a sale for 19% off its original price if the total l cost includes a 5% sale
    15·2 answers
  • -5(4m - 2) = -2/3 + 6m).​
    8·1 answer
  • You and your friends decide to camp for one night. Look at the diagram of your tent below. It is drawn on 1 cm squared paper. Th
    15·2 answers
  • Define function *it’s for math pls help asap*
    15·1 answer
  • Miles incorrectly gave the product of 7 * 2.6 as 14 * 42 to use a place value chart or an area model to help miles understand hi
    15·1 answer
  • Pls help pls pls hii lol bye hahaha math fractions lol. videostar
    7·1 answer
  • Please select the best answer from the choices provided<br>A<br>B<br>C<br>D​
    14·1 answer
  • How many rotational symmetries does a regular octagon has and how many lines of reflection symmetry does a regular octagon has?
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!