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2 years ago

Find the volume of the sphere. Round your answer to the nearest tenth.

Mathematics

1 answer:

ollegr [7]2 years ago

6 0

Answer:

Step-by-step explanation:

Givens

pi = 3.14

d = 3.8

r = d/2

r = 3.8/2 = 1.9

Formula

V = (4/3) * pi * r^3

Solution

V = (4/3) * 3.14 * 1.9^3

V = 4/3 * 3.14 * 6.859

V = 28.7163

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

Anit [1.1K]

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)

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

7 0

3 years ago

1- ? divided by 3 = -7 <br> 2- -50 divided by ? =10<br> 3- ? divided by -2 = 10

vagabundo [1.1K]

1.) -21
2.) 5
3.) -20
bdhdhdhfh

8 0

3 years ago

A statistics student would like to estimate the average age of students at her college. She would like to be 99% confident that

agasfer [191]

Answer:

Step-by-step explanation:

Given that a statistics student would like to estimate the average age of students at her college.

Population std dev =2.5years

For 99% , Z critical = ±2.59

Margin of error = $±2.59*\frac{2.5}{\sqrt{n} } \\= \frac{±6.475}{\sqrt{n} } =0.5$

Simplify to get

$\sqrt{n} =12.95$

n = 167.70

n=168

She must survey 168 people

7 0

3 years ago

Sorry the last one i put was the wrong one haha

Lunna [17]

Answer:

Step-by-step explanation:

In 7 years, Jose will be his age + 7 years.

5 0

3 years ago

Read 2 more answers

Please help me please

Setler79 [48]

Answer:

Step-by-step explanation:

8 0

2 years ago