9) Refer to the table which summarizes the results of testing for a certain disease.
Positive Test Negative Test
Result Result
Subject has the disease
Subject does not have the disease
111
11
4
172
one of the results is randomly selected, what is the probability that it is a false negative (test
indicates the person does not have the disease when in fact they do)? What does this probability
suggest about the accuracy of the test?
A) 0.591, The probability of this error is high so the test is not very accurate.
B) 0.0348, The probability of this error is low so the test is fairly accurate.
C) 0.0134; The probability of this error is low so the test is fairly accurate.
D) 0.0369; The probability of this error is low so the test is fairly accurate.

step-by-step explanation: 4 cause 2+2=4

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have

let x and 400 - x be the two numbers.  

==> 0.80x + 0.85(400 - x) = 400 - 68 from the statement of the problem.  

< ==> 0.80x + 0.85(400 - x) = 400 - 68  

==> 340 - 0.05x = 332  

< ==> -0.05x = -8 ==> x = 160, the first number ==> 400 - x = 240, the second number.