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:
0
Step-by-step explanation:
Substitute the given values for a and b into the expression
(18 + 14) - (18 - 14)²
=
× 32 - 4²
= 16 - 16
= 0
Answer:
The positive value of
will result in exactly one real root is approximately 0.028.
Step-by-step explanation:
Let
, roots are those values of
so that
. That is:
(1)
Roots are determined analytically by the Quadratic Formula:


The smaller root is
, and the larger root is
.
has one real root when
. Then, we solve the discriminant for
:


The positive value of
will result in exactly one real root is approximately 0.028.
Answer:
It's a positive 8.
Step-by-step explanation:
You can't have a negative amount of money.
Answer:
Step-by-step explanation:
it's even because f(-x)=f(x)