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
DENIUS [597]
3 years ago
14

A new screening test for Lyme disease is developed for use in the general population. The sensitivity and specificity of the new

test are 60% and 70%, respectively. Three hundred people are screened at a clinic during the first year the new test is implemented. Assume the true prevalence of Lyme disease among clinic attendees is 10%.
Calculate the following values:

The predictive value of a positive test

The predictive value of a negative test
Mathematics
1 answer:
Anit [1.1K]3 years ago
7 0

Answer:

predictive value of a positive test = 18.18%

predictive value of a negative test = 94.03%

Step-by-step explanation:

Sensitivity = 60% = 0.6

Specificity = 70% = 0.7

Let True Positive = TP

True Negative = TN

False Negative = FN

Sensitivity = \frac{TP}{TP + FN} \\0.6 = \frac{TP}{TP + FN} \\0.6TP + 0.6FN = TP\\0.4TP = 0.6FN\\TP = 1.5 FN

Specificity = \frac{TN}{TN + FP} \\0.7 = \frac{TN}{TN + FP} \\0.7TN + 0.7FP = TN\\0.7FP = 0.3 TN\\TN  = 7/3 FP

Prevalence = 10% = 0.1

Three hundred people are screened, T_{total} = 300

Total number of people having the disease, T_{disease} = ?

Prevalence = \frac{T_{disease} }{T_{total} } \\0.1 =  \frac{T_{disease} }{300 }\\T_{disease} = 30

T_{disease} = TP + FN\\30 = TP + FN

But TP = 1.5 FN

30 = 1.5 FN + FN

30 = 2.5 FN

FN = 30/2.5

FN = 12

TP = 1.5 FN = 1.5 * 12

TP = 18

FP + TN = T_{total} - T_{disease} \\FP + TN = 300 - 30\\FP + TN = 270\\FP + \frac{7}{3} FP = 270\\\frac{10}{3} FP = 270\\FP = 27 * 3\\FP = 81

81 + TN = 270

TN = 189

To calculate the Predictive value of positive test (PPT)

PPT = \frac{TP}{TP + FP} * 100\\PPT = \frac{18}{18+81} * 100\\PPT = \frac{18}{99} * 100\\PPT = 18.18 \%

To calculate the Predictive value of negative test (PNT)

PPT = \frac{TN}{FN + TN} * 100\\PPT = \frac{189}{189+12} * 100\\PPT = \frac{189}{201} * 100\\PPT = 94.03 \%

You might be interested in
-2-(-5) = -2 + (-5)<br> 2- =
zzz [600]

Answer:

-4 Is the answer I think hope it will help u

3 0
3 years ago
Read 2 more answers
A cylinder has a height of 6 meters and a radius of 3 meters. What is its volume? Use ​ ≈ 3.14 and round your answer to the near
bija089 [108]

Answer:

169.56 m³

Step-by-step explanation:

» <u>Concepts</u>

The volume of a cylinder is how much space there is inside the cylinder. The formula to find the volume is πr²h, where r = radius and h = height. Once you get the volume, you have to add <unit>³.

» <u>Application</u>

We are given the radius as three meters and the height as six meters; we also have to use π as 3.14. Now, we just have to plug in these values into the aforementioned formula.

» <u>Solution</u>

  • <u></u>3.14*3^3*6
  • 3.14*9*6
  • 28.26*6
  • 169.56
7 0
2 years ago
Which is the graph of f(x)= √x
4vir4ik [10]

Answer:

ion know

Step-by-step explanation:

you figure it out

5 0
3 years ago
Choose all statements that show correct reasoning for finding 15 divided by 2/9
skelet666 [1.2K]

Answer:

The second and the last options.

Step-by-step explanation:

15/ 2/9 =67.5 Solve the original problem

15*2/9 =3.33333333333

15*9/2 =67.5

(15* 1/9) /2=0.833333333333333

15*9* 1/2 =67.5

8 0
2 years ago
Read 2 more answers
Two balls A and B rotate along a circular track. Ball A makes 4 full rotations in 120 seconds. Ball B makes 3 full rotation in 6
lara [203]
Find the rate in which both balls make one full rotation around the track.

Ball A:

120 / 4 = 30

It takes 30 seconds for Ball A to make a full rotation.

Ball B:

60 / 3 = 20

It takes 20 seconds for Ball B to make a full rotation.

Find the least common multiple of 20 and 30 to find the time at which they'll meet.

Multiples of 20: {20,40,60}
Multiples of 30: {30,60}

60 is the least common multiple of both 20 and 30.

The balls will meet again at 60 seconds.
5 0
3 years ago
Other questions:
  • (4x^2-10x+6) divide (4x+2)
    6·1 answer
  • Evaluate each expression <br> 6p3 <br> If p= -4
    11·2 answers
  • What is the length of the line segment with endpoints (11, −4) and (−12, −4)?
    14·2 answers
  • Phillips help me solve this problem I don’t understand first to answer will be marked brainlyest
    15·2 answers
  • A quadratic equation has exactly one real number solution. Which is the value of its discriminant?
    13·1 answer
  • 18.<br> 64°<br> 34<br> 9<br> Is this correct
    6·1 answer
  • 1. At dinner Mr. Murphy’s bill came out to $39.99 before tax and tip sales tax is 6% he wants to also have a 20% tip how much mo
    10·1 answer
  • What was Captain Hook's name before he got the hook?
    15·2 answers
  • HELP PRETTY PLEASEE !!!!!!!!!!!!
    10·2 answers
  • Which ratio in the form A:B is equivalent to the ratios in
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!