<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.
40xa^2 + 24 ax + 32 a =
all you have to do is factor out a 8a from each term
aka reverse distribution property
8a (5 a + 3x + 4)
Answer: 3, 5, 7
Step-by-step explanation:
There is a "trick" to determine divisibility by 3: if the sum of the digits is divisible by 3, the number is divisible by 3.
3 + 1 + 5 = 9 which is a multiple of 3, so 315 is divisible by 3.
It works for 9 also. since the sum of the digits is 9, 315 is divisible by 9.
Divisibility by 5: any number that has the units digit 5 or 0 is divisible by 5.
For 7, I just tried it 315÷7= 45
Only even numbers are divisible by 2.
If a 3-digit number is divisible by 11, the middle digit will be the sum of the first and last digits. (That is not the case for 315) But 385 is divisible by 11, also 495, 253, and many others you can try for fun.
Answer:
Step-by-step explanation:
-7x + 12 + (-8x + 48) = 180
-15x + 60 = 180
-15x = 120
x = -8
m<BDC= -7(-8)+ 12 = 56 + 12 = 68
m<CBA = -8(-8)+48 = 64+48 = 112
Answer:
The diameter is 3 inches
Step-by-step explanation:
If you are calculating a circle, one of the main rules you should know is that the diameter is double the radius. In this case the radius is 1.5 inches long. If you need the diameter, you need to double that figure; in this case the answer is 3 inches
