Answer: 
Step-by-step explanation:
The confidence interval for population mean is given by :-

Given : Sample size : n= 35 , large sample (n>30)
Mean difference : 
Standard deviation : 
Significance level : 
Critical value : 
Now, the 99.9% confidence interval for the mean difference between the marks scored last week and marks scored this week by all the students will be :-

Hence, the 99.9% confidence interval for the mean difference between the marks scored last week and marks scored this week by all the students = 
She started with 81 baseball cards.
The range is the output or the y values in the case of this function. The only y value on this function is 1 therefore the range is 1
Answer:
The only thing I can think of is that you miss-typed out the question. None of these work :/
Answer:
-7
Yep you were right!
Step-by-step explanation:
-3+2(-2)
-3+-4
-7