Suppose the germination periods, in days, for grass seed are normally distributed. If the population standard deviation is 3 days, what minimum sample size is needed to be 90% confident that the sample mean is within 1 day of the true population mean? z0.101.282z0.051.645z0.0251.960z0.0 12.326z0.0052.576 Use the table above for the z-score, and be sure to round up to the nearest integer.

The minimum sample size is needed to be 90% confident that the sample mean is within 1 day of the true population mean is 25.

Step-by-step explanation:

We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of .

So it is z with a pvalue of , so

Now, find the margin of error M as such

In which is the standard deviation of the population and n is the size of the sample.

If the population standard deviation is 3 days, what minimum sample size is needed to be 90% confident that the sample mean is within 1 day of the true population mean?

This is n when . So

Rouding up to the nearest integer, 25.

The minimum sample size is needed to be 90% confident that the sample mean is within 1 day of the true population mean is 25.

answer: standard form is ax^2 + bx + c = 0

step-by-step explanation:

standard form is ax^2 + bx + c = 0

(2x + 1)(x - 2) = 0

distribute to get into standard form

2x^2 - 4x + x - 2 = 0

2x^2 - 3x - 2 = 0

a = 2, b= -3, c = -2

a is your answer

step-by-step explanation:

(3rd option) - c