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.
Either use a graphing calculator or substitute the value of x for x
A mean is an arithmetic average of a set of observations. The score that Taylor needs to make in her eleventh test for the average to be 87 is 93.
<h3>What is Mean?</h3>
A mean is an arithmetic average of a set of observations. it is given by the formula,
Mean = (Sum of observations)/Number of observations
The score earned by Taylor in her first 10 test are 78, 92, 98, 87, 86, 72, 92, 81, 86, 92. Also, she wants the average to be 87, therefore, we can write,
(78 + 92 + 98 + 87 + 86 + 72 + 92 + 81 + 86 + 92 + x)/11 = 87
864 + x = 957
x = 93
Hence, The score that Taylor needs to make in her eleventh test for the average to be 87 is 93.
Learn more about Mean:
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Answer:
The balance of the loan will be approximately $15,000. - Month 16
The balance of the loan will reach $0. - Month 50
Write 3 four times and multiple them together. Then, write out 5 two times and multiple it together. Whatever those two answers are, subtract them
