Answer:
3.5
Step-by-step explanation:
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.
She'll have traveled approximately 431.07 km in 8.5 hours, also, 267.85448 miles per hour.
In decimal form that would be 36.052
Step-by-step explanation:
Distance = rate × time
If b is the speed of the boat in still water, and c is the speed of the current, then:
60 = (b + c) × 4
35 = (b − c) × 3.5
Simplifying:
15 = b + c
10 = b − c
Add the equations together:
25 = 2b
b = 12.5
Plug into either equation to find c:
c = 2.5
The speed of the boat is 12.5 km/h, and the speed of the current is 2.5 km/h.
