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).
Infinite intervals are closed if they contain a finite endpoint, and open otherwise. The entire real line is an infinite interval that is both open and closed
Answer:
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<u>pelo</u>
Step-by-step explanation:
ok que se puede decir que no la encuentro por la noche y que me voy para allá para allá para que me den una solución y me voy para allá y voy saliendo de ahí
Answer:
x = -4 y = -5
Step-by-step explanation:
2x + 3 = -x - 9
3x + 3 = -9
3x = -12
x = -4
y = - (-4) - 9
y = 4 - 9
y = -5
D because is the equal to the other side but added allá together