Answer:
3
Step-by-step explanation:
Missing part of the question
Determine the number of handshakes, i, that will occur for each number of people, n, in a particular room. (people)
Answer:

Step-by-step explanation:
Given
For 5 people

Using the given instance of 5 people, the number of handshakes can be represented as:

The above sequence is an arithmetic sequence and the total number of handshakes is the sum of n terms of the sequence.

Where
--- The first term
--- The last term
So:


Answer:
The 98% confidence interval for the mean purchases of all customers is ($37.40, $61.74).
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find M as such

In which
is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the mean subtracted by M. So it is 49.57 - 12.17 = $37.40.
The upper end of the interval is the mean added to M. So it is 49.57 + 12.17 = $61.74.
The 98% confidence interval for the mean purchases of all customers is ($37.40, $61.74).
Answer:
(x - 3)(x + 1)(x + 5)
Step-by-step explanation:
I'd use synthetic division instead. If we were to find the roots of the given polynomial, we could from them write the factors as well.
The divisor x + 5 corresponds to root x = -5. Setting up synthetic div.,
-5 ) 1 3 -13 -15
-5 10 +15
-----------------------------
1 -2 -3 0
Since the remainder is 0, we know that -5 is a root and (x + 5) is a factor. Moreover, we know that the coefficients of the quotient are 1, -2 and -3.
1x² - 2x - 3 can be factored: the factors are (x - 3) and (x + 1).
So the end result for this problem is (x - 3)(x + 1)(x + 5).