84(1/7)+9(1/3)
The 84 is divided by the 1/7th and the 9 is divided by the 1/3. They are then added.
Answer:
The 99% confidence interval for the mean number of hours of part-time work per week for all college students is between 25.8 and 30.2.
Step-by-step explanation:
A confidence interval has the following format.

In which
is the mean of the sample and M is the margin of error.
In this problem, we have that:



The 99% confidence interval for the mean number of hours of part-time work per week for all college students is between 25.8 and 30.2.
ANSWER

EXPLANATION
The given sequence is
3,-5,-13,.....-229.
The first term of this sequence is
a_1=3
There is a common difference of

The last term of this sequence is -229.
The nth term of this sequence is given by:

We use the last term to determine the number of terms in the sequence.



Divide through by -8;


Hence there are thirty terms in the sequence.
The sum of the first n terms is given by:

The sum of the first 30 terms is given by:



Answer:
i think it's the subtraction one
Step-by-step explanation:
because if you find out what b is maybe you will get 2 1/2