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4 years ago

5

? Nancy decided to take a cab instead of the bus for an 8-mile trip. What is the difference between the bus fare and the cab far

e for 8 miles

1 answer:

raketka [301]4 years ago

4 0

Where are the numbers?

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I don'r really understand as a quick summary what are the odd and even functions of these equations?

Sloan [31]

Answer:

you need to add the equations in my guy

Step-by-step explanation:

8 0

3 years ago

A painting is 24 in. Wide by 32in. Long. The width of a postcard reductions of the painting is 3in. How long is the postcard

s344n2d4d5 [400]

Answer:

4 inches.

Step-by-step explanation:

24 32

---- = -----

3 x

Cross multiply.

24x = (32)(3) = 96.

96 / 24 = 4.

Hope this helped and good luck! (:

7 0

3 years ago

Gerry visited a farm and saw a total of 87 chickens and pigs. If there were a total of 248 legs between all of these animals, ho

Shkiper50 [21]

Answer: 37

Step-by-step explanation:

87 x 2 = 174

248 - 174 = 74

74 divided by 2 = 37

So, therefore you answer will be 37

:))

6 0

3 years ago

How do I get from: <br>Sin x = -1/2<br>To: x = 7Pi/6, 11Pi/6

brilliants [131]

A few ways. you can enter it into a calculator for one, but the easiest way would be to reference a unit circle and look for an ordered pair where sin (the y value), is equal to -1/2

on a unit circle, the sin value is -1/2 at 7pi/6 and 11pi/6

because sin is the y value, it will additionally be in the quadrants III or IV based on the fact that (-1/2) as a sin value IS a negative and would have to be found in a quadrant in which sin is negative (the lower half of a coordinate plane, in this case)

8 0

3 years ago

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