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).
9.8 pounds in ounces is 156.8
Hope this helped!!
Answer:
The answer is 100
Step-by-step explanation:
2 times 2=4 4 times 5=20 20 times 5/5 times 2=10 then add a zero
We know that
the law of sines established
a/sin A=b/sin B--------sin A=[a*sin B]/b
a=4.5 cm
b=6 cm
B=35°
so
sin A=[4.5*sin 35°]/6-----> sin A=0.43018
A=arc sin(0.43018)-------> A=25.5°
the answer is the option
<span>C) 25.5° </span>
Plug it in
7(4) + 8(5) which would be 28 + 40
Answer: 68