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.
Answer: The number 5 in 56 is in the tenths place.
Answer: It will take 4 seconds for the rock to hit the water.
Step-by-step explanation:
Given : Benjamin threw a rock straight up from a cliff that was 48 ft above the water.
If the height of the rock h, in feet, after t seconds is given by the equation
To find : Time taken for the rock to hit the water.
When rock hit the water height becomes zero , i.e. put h = 0 , we get
Divide equation by 2 , we get
The Laue of x for ax²+bx+c =0 is 
So , 
Since t cannot be negative , so t= 4
Hence, it will take 4 seconds for the rock to hit the water.
