Multiplication, hope I could help!
Answer:
We accept the null hypothesis and the population mean is $120.
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 100
Sample mean,
= $120
Alpha, α = 0.01
Sample standard deviation, s = $25
First, we design the null and the alternate hypothesis
We use two-tailed t test to perform this hypothesis.
Formula:

Putting all the values, we have
p-value one tail= 0.024
p-value two tail= 0.048
Conclusion:
Since the p-value for two tailed test is greater than the significance level, we fail to reject the null hypothesis and accept it.
Thus, the population mean is $120.
Answer:
0.3 or 30%
Step-by-step explanation:
The professors will only seek a smaller publisher if they cannot place the statistics book with a major publisher. If the probability of getting a major publisher is 40% and the probability of getting a smaller publisher is 50%, then the probability that the statistics book would wind up being placed with a smaller publisher is given by:

The probability is 0.3 or 30%.
Answer:
The no. of possible handshakes takes place are 45.
Step-by-step explanation:
Given : There are 10 people in the party .
To Find: Assuming all 10 people at the party each shake hands with every other person (but not themselves, obviously) exactly once, how many handshakes take place?
Solution:
We are given that there are 10 people in the party
No. of people involved in one handshake = 2
To find the no. of possible handshakes between 10 people we will use combination over here
Formula : 
n = 10
r= 2
Substitute the values in the formula





No. of possible handshakes are 45
Hence The no. of possible handshakes takes place are 45.