The last one is the answer
Answer:

Step-by-step explanation:
The confidence interval for the population mean x can be calculated as:

Where x' is the sample mean, s is the population standard deviation, n is the sample size and
is the z-score that let a proportion of
on the right tail.
is calculated as: 100%-99%=1%
So, 
Finally, replacing the values of x' by 308, s by 17, n by 15 and
by 2.576, we get that the confidence interval is:

Slope intercept form: y = mx + b
mx = slope
b = y-intercept
We know the y intercept is 0, so nothing will be written there.
To find the slope of this line, we can use the slope formula.

We'll use the points (1, 0) and (3, 1) to find the slope.
Now we can just plug these values into the equation to find the slope.
1 - 0 / 3 - 1
1 / 2
The slope of the line is 1/2, or 0.5.
The slope-intercept form of this line can be written as:
y = 0.5x
Answer:
Value of x is used to consider unknown value. The letter “x” is commonly used in algebra to indicate an unknown value. It is referred to as a “variable” or, in some cases, a “unknown.” In x + 2 = 7, x is a variable. ... A variable need not be “x,” but might be “y,” "w," or any other letter, name, or symbol.
Answer:
75/99
Step-by-step explanation: