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 =
Answer: 5x+8
Step-by-step explanation: You have to combine like terms.
3x+2x=5x
5+3=8
= 5x+8
More than means addition.
C is the correct option.
= (2x + 4) + 9 - 4y + 3x
= 2x + 4 + 9 - 4y + 3x
= 5x + 13 - 4y
= 5x - 4y + 13
Answer:
Jenna sold 280 boxes, Becca sold 105 boxes.
Step-by-step explanation:
For every 3 boxes B sold, J sold 8 boxes and ended with a total of 385 boxes sold.
3b+8j=385
From how the question is asked, we can assume that each round of sales would equal 11 total sales. (3b+8j=11)
Knowing the sales take place in intervals of 11, we can solve the problem by doing 385/11.
385/11=35
Finally, with 35 rounds of sales happening and knowing Jenna sells 8 while Becca sells 3 at each one, all that's left to do is multiply.
8x35=280
3x35=105
To be sure we can check our answer by adding them together, 280+105=385.
