Y= mx+b is the formula for writing and equation for slope.

M= slope
B= y-intercept

You replace the m and b with the info given to you in the problem.

Answer: y = -3/4x -6

6 0

3 years ago

The cost of a whole box of chips are $60. I have $48. What percentage of the total cost do I have?

goblinko [34]

Answer:

Percentage of total I have = 80%

Step-by-step explanation:

Given:

Price of Box = $60

I Have = $48

To Find:

Percentage I have = ?

Solution:

In this question we are just supposed to find out the percentage of the Value we have so

Percentage can be found by the formula

Percentage $=\frac{Given Value}{Total}*100$ %

Now we have the values of all

So putting in the values

Percentage $=\frac{48}{60}*100$ %

$=\frac{4800}{60}$ %

= 80%

So the Percentage of total cost I have is 80%

Percentage of total = 80%

4 0

2 years ago

Twenty more than four times a number is equal to the difference between 139 and three times the number. Find the number.

Lady_Fox [76]

Answer:

x = 17

Step-by-step explanation:

First, let's turn this into an equation:

twenty more ( +20 ) than four times a number ( 4x ) is equal ( = ) to the difference ( - ) between 139 and 3 times the number ( 3x ).

4x + 20 = 139 - 3x

Now let's solve:

Subtract 20 from each side:

4x = 119 - 3x

Add 3x to each side:

7x = 119

Divide each side by 7:

x = 17

5 0

2 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