<h2>
Answer with explanation:</h2>
Let be the population mean.
By observing the given information, we have :-
Since the alternative hypotheses is left tailed so the test is a right-tailed test.
We assume that the time spend by students per day is normally distributed.
Given : Sample size : n=121 , since n>30 so we use z-test.
Sample mean :
Standard deviation :
Test statistic for population mean :-
Critical value (one-tailed) corresponds to the given significance level :-
Since the observed value of z (-7.79) is less than the critical value (1.2816) , so we do not reject the null hypothesis.
Hence, we conclude that we have enough evidence to accept that the college students spend an average of 4 hours or less studying per day.
Answer:
(x-1)² = 3
Step-by-step explanation:
Given f(x)=x²−2x−2
Completing x²−2x−2 = 0 to square
- x²−2x − 2=0
- x²−2x + 1 - 3 =0
- (x - 1)² - 3 = 0
- (x - 1)² = 3
Correct choice is D
9514 1404 393
Answer:
5 seconds
Step-by-step explanation:
Suppose the front parts of the trains meet at point A. Since both are the same length and traveling the same speed, each will pass point A in time ...
time = distance/speed
time = (1/18 mi)/(40 mi/h) = (1/720 h) × (3600 s)/(1 h) = 5 s
That is, the rear part of each train will be at point A 5 seconds after the front part.
The rear parts will pass each other 5 seconds after the front parts meet.
(10(1-(1/2)^5)/1-(1/2) =
20(1-1/32)
=155/8
Answer:
x is 3
and
y is 3
Step-by-step explanation:
(2*3)+(3*3) = 15
6+9 = 15