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
Lesechka [4]
3 years ago
9

For a medical study, a researcher wishes to select people in the middle 60% of the population based on blood pressure.

Mathematics
1 answer:
Finger [1]3 years ago
4 0

Answer:

Lower limit: 113.28

Upper limit: 126.72

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean \mu and standard deviation \sigma, the zscore of a measure X is given by:

Z = \frac{X - \mu}{\sigma}

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

\mu = 120, \sigma = 8

Middle 60%

So it goes from X when Z has a pvalue of 0.5 - 0.6/2 = 0.2 to X when Z has a pvalue of 0.5 + 0.6/2 = 0.8

Lower limit

X when Z has a pvalue of 0.20. So X when Z = -0.84

Z = \frac{X - \mu}{\sigma}

-0.84 = \frac{X - 120}{8}

X - 120 = -0.84*8

X = 113.28

Upper limit

X when Z has a pvalue of 0.80. So X when Z = 0.84

Z = \frac{X - \mu}{\sigma}

0.84 = \frac{X - 120}{8}

X - 120 = 0.84*8

X = 126.72

You might be interested in
Factor completely 3x(x + 2) + 4(x + 2). (1 point) (x + 2)(7x)
Nezavi [6.7K]

ANSWER

(x + 2)(3x + 4)

EXPLANATION

The given expression is

3x(x + 2) + 4(x + 2)

We can see that (x+2) is the greatest common factor.

We factor to obtain;

(x + 2)( 3x + 4)

The correct choice is C.

6 0
3 years ago
The perimeter of a square is 20. Find the length of the diagonal
klemol [59]

Answer:

d≈7.07

Step-by-step explanation:

Using the formulas

P=4a

d= \sqrt{2} a

Solving ford  

d= \sqrt{2} P/4=2·20 /4≈7.07107

8 0
2 years ago
Read 2 more answers
Jessica finished a race that was 5 miles long in 30 minutes and 15 seconds. Casey finished a race that was 2 miles log in 11 min
poizon [28]

Answer:

Casy

Step by step explanation:

You divide the miles by their time

It took Jessica 6 minutes and .03 seconds to finish a mile

It took Casy 5 minutes and 54 seconds to finish a mile

Casy is .09 Seconds quicker than Jessica

3 0
3 years ago
Someone please help me, use a variable to represent the situation, and solve the equation using inverse operations.
Scorpion4ik [409]

Answer:

36 in

Step-by-step explanation:

T= toucan

M= macaw

T= 2/3M

T= 24

24= 2/3M

72=2M

36= M

4 0
2 years ago
Read 2 more answers
£90 is divided between Mark, Henry & Gavin so that Mark gets twice as much as Henry, and Henry gets three times as much as G
Phantasy [73]

Answer:

Mark gets £54

Step-by-step explanation:

Let Gavin share=x

Henry=3x

Mark=2(3x)

x+3x+2(3x)=£90

x+3x+6x=£90

10x=£90

x=9

Gavin=x=£9

Henry=3x

=3(9)=£27

Mark=2(3x)

=2(3*9)

=2(27)

=£54

4 0
3 years ago
Other questions:
  • HELP!!!!
    6·1 answer
  • You need to solve for x and y .
    7·1 answer
  • A pole, 4m high, stands, vertically, on
    13·1 answer
  • If f(x)=x-2, which of the following is the inverse of F(x)
    12·2 answers
  • A motorist traveled 6km in 30 mins
    14·1 answer
  • Z+11≤17<br> What is the answer?
    12·1 answer
  • Your mother has asked for your help. She would like to save up $30,000 to take your family on a trip in 3 years. She wants to ma
    11·2 answers
  • If each iTunes song costs $0.99 and Wade bought 24 songs, how much was the total cost?
    14·2 answers
  • Which none of the following is a solution of the system
    13·1 answer
  • PLEASE ANWSER CORRECTLY!! I WILL MARK BRAINIEST!!!
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!