<span>A statistical question is one that can be answered by collecting data and where there will be variability in that data.</span>
Answer and Step-by-step explanation:
a)
expected value for the difference in sample means=3.5-3.2=0.3
b)
standard deviation of the sampling distribution of the difference in sample means
=sqrt((0.5^2/40)+(0.8^2/40))
=0.1492
c)
z=(0.3-0)/0.1492
z=2.01
P(z>2.01)=0.0222
Answer: 9
Step-by-step explanation:
first u have to add up all the numbers "12 + 2 + 9 + 12 + 10" and that's 45 then u have to divide by how many numbers there are, so there's 5 numbers. ur dividing "45/5" which is 9 so the mean is 9
mark as brainly plss