Answer:
Step-by-step explanation:
As x = 0 is a zero, (x + 0) is a factor.
Dividing the equation by (x + 0) leaves x² - 9x + 20.
Factoring this polynomial
x² - 9x + 20 = (x - 4)(x - 5)
x - 4 = 0
x = 4
x - 5 = 0
x = 5
The zeros are at 0, 4, and 5.
Which can be verified by using a plotting calculator.
No, this is not a plausible value for the population mean, because 5 is not within the 95% confidence interval.
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Explanation:
The greek letter mu is the population mean. It has the symbol which looks like the letter 'u' but with a tail at the front or left side.
The question is asking if mu = 5 is plausible if the researcher found the 95% confidence interval to be 5.2 < mu < 7.8
We see that 5 is <u>not</u> in that interval. It's a bit to the left of 5.2
Since mu = 5 is not in the interval, it's not a plausible value for the population mean.
Have we ruled it out with 100% confidence? No. Such a thing is not possible. There's always room for (slight) error. The researcher would need to do a census to be fully confident; however, such practices are very time consuming and expensive. This is the main reason why statistics is important to try to estimate the population with a sample.
Ratios be 2x and 3x
Now