Answer:
6
how:
add up all the numbers the divide by the amount of numbers given.
Use:
First, I added all the numbers up and got 48.
Next, I divided by 8.
Last, I did 42 divided by 8 and got 6.
The mean is 6.
Answer:
B.
Step-by-step explanation:
So there are 16 grams initally. Then, the amount of water decreases by 3.5%.
So first we must find 3.5% of 16. 3.5% in decimal form is 0.035, since you divide 3.5 by 100. Then, when you multiply 0.035 by 16, you get 0.56. Since the solution decreased by that percentage, you must subtract 0.56 from 16, which is 15.44.
Then the amount of water decreases by 4.25%. That in decimal form is 0.0425. You multiply it by 15.44, and it comes out to 0.6562. You subtract that from 15.44, not 16, since some of the water has evaporated. So you get 14.7838.
Answer:
Step-by-step explanation:
We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean
For the null hypothesis,
µ = 17
For the alternative hypothesis,
µ < 17
This is a left tailed test.
Since the population standard deviation is not given, the distribution is a student's t.
Since n = 80,
Degrees of freedom, df = n - 1 = 80 - 1 = 79
t = (x - µ)/(s/√n)
Where
x = sample mean = 15.6
µ = population mean = 17
s = samples standard deviation = 4.5
t = (15.6 - 17)/(4.5/√80) = - 2.78
We would determine the p value using the t test calculator. It becomes
p = 0.0034
Since alpha, 0.05 > than the p value, 0.0043, then we would reject the null hypothesis.
The data supports the professor’s claim. The average number of hours per week spent studying for students at her college is less than 17 hours per week.