Answer:
It intersects the x-axis at x = 10
Step-by-step explanation:
Step 1: Find slope <em>m</em>
m = (5 - 1)/(5 - 9)
m = 4/-4
m = -1
y = -x + b
Step 2: Find <em>b</em>
5 = -5 + b
b = 10
Step 3: Rewrite equation
y = -x + 10
Step 4: Find <em>x</em> when <em>y</em> = 0
0 = -x + 10
-10 = -x
x = 10
So the graph crosses the x-axis at 10.
Answer:
As the sample size increases, the variability decreases.
Step-by-step explanation:
Variability is the measure of actual entries from mean. The less the deviations the less would be the variance.
For a sample of size n, we have by central limit theorem the mean of sample follows a normal distribution for random samples of large size.
X bar will have std deviation as 
where s is the square root of variance of sample
Thus we find the variability denoted by std deviation is inversely proportion of square root of sample size.
Hence as sample size increases, std error decreases.
As the sample size increases, the variability decreases.
You're looking for a value

such that

Because the distribution is symmetric, the value of

in either case will be the same.
Now, because the distribution is continuous, you have that

The mean for the standard normal distribution is

, and because the distribution is symmetric about its mean, it follows that

.

You can consult a

score table to find the corresponding score for this probability. It turns out to be

.