We can use the sum of an aritmetic sequence
the sum from n=1 to n=r when the first term is a1 and the nth term is an is

first term is 1
last term is 100
there are 100 terms so n=100
so the sum is


S=5050
now you want us to divide by 10
5050/10=505
fun fact, gauss (famous math guy) did this when he was younger, legend has it that he was assigned this as an in class assigment to kill time but gauss found a neat pattern, he noticed that adding the end terms wer giving the same sum, example, 100+1=101, 2+99=101, etc, so he just needed to find al the pairs and add them all up
answer is 505
the result is 505
Answer:
The 95% confidence interval of the mean time it took a person to find their dream home is between 5.64 months and 6.16 months.
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 the margin of error 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 sample mean subtracted by M. So it is 5.9 - 0.26 = 5.64 months
The upper end of the interval is the sample mean added to M. So it is 5.9 + 0.26 = 6.16 months.
The 95% confidence interval of the mean time it took a person to find their dream home is between 5.64 months and 6.16 months.
Answer:
4 and 5
Step-by-step explanation:
Make a system of equations:
x+y=9
x-y=-1
x=9-y
9-y-y=-1
9-2y=-1
-2y=-10
y=5
Since y=5, x must be 4 since 4+5=9 and 4-5=-1
Hope this helped!