Answer:
The 80% confidence interval for the the population mean nitrate concentration is (0.144, 0.186).
Critical value t=1.318
Step-by-step explanation:
We have to calculate a 80% confidence interval for the mean.
The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.
The sample mean is M=0.165.
The sample size is N=25.
When σ is not known, s divided by the square root of N is used as an estimate of σM:
The degrees of freedom for this sample size are:
The t-value for a 80% confidence interval and 24 degrees of freedom is t=1.318.
The margin of error (MOE) can be calculated as:
Then, the lower and upper bounds of the confidence interval are:
The 80% confidence interval for the population mean nitrate concentration is (0.144, 0.186).
Answer:
answer of 4r/4s is going to be r/s
Step-by-step explanation:
because 4 divided by 4 is 1 which leaves r/s
Answer: y = -3
<u>Step-by-step explanation:</u>
-8x - 5y = -1
<u>+8x </u> <u>+8x </u>
-5y = 8x - 1
<u> ÷-5 </u> <u> ÷-5</u> <u>÷-5</u>
y =
y(2) =
=
=
= -3