Answer:
The probability of testing positive for one is 0.20.
The probability of testing negative for one sample is (1-0.2)=0.8.
We only save time when all five are negative, which has a probability of 0.8^5=0.32768.
This means that the expected number of tests is
combined sample tests negative = 1 with probability 0.32768
combined sample tests positive = 1+5 retests = 6 with probability 0.67232
Expected number of tests
=Σ nipi / n
=(1*0.32768+6*0.67232)/5 [divide by 5 because we tested 5 samples]
= 0.87232 < 1
So yes, there is a saving.
Note: In practice, all medical tests are not absolute, i.e. they give false-positives(α) and false-negatives (β). The ratios 1-α and 1-β are respectively measures of specificity and sensitivity.
These two parameters complicate the simplistic evaluation above.
Answer:
D
Step-by-step explanation:
4C1*5C1*6C1*8C1
=960
The measure of the acute angle that the wire makes with the ground is 63.27°.
The situation forms a right angle triangle.
<h3>How to find the angle of a right triangle?</h3>
The length of the wire is the hypotenuse of the right triangle.
The distance from the foot of the pole is the adjacent side of the right triangle.
Therefore,
cos ∅ = adjacent / hypotenuse
cos ∅ = 18 / 40
cos ∅ = 0.45
∅ = cos⁻¹ 0.45
∅ = 63.2563160496
∅ = 63.27°
learn more on right angle triangle here: brainly.com/question/14866099
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Yes! 40:70 can be simplified! A ratio can be simplified if both numbers have a GCF that is not 1. Looking at 40 and 70, we see that they have a GCF of 10. That means that to simplify 40:70, we need to divide both numbers by 10. 40/10 = 4, and 70/10 = 7, so that means that our simplified ratio is 4:7.
