Answer:
The margin of error of the 90% confidence interval of a student's average typing speed is of 1.933 wpm.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 20 - 1 = 19
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 19 degrees of freedom(y-axis) and a confidence level of
. So we have T = 1.7291
The margin of error is:

In which s is the standard deviation of the sample and n is the size of the sample. For this question, we have
. So



The margin of error of the 90% confidence interval of a student's average typing speed is of 1.933 wpm.
3 because the 2z minus the 3 gives you 1 rounded
Answer:
0.5% error
Step-by-step explanation:
We can use the percentage error formula, which is
.
We know that the approximated value was 8.04, however it is actually 8cm, so we can substitute inside the equation.

Hope this helped!
Answer:
slope is undefined
Step-by-step explanation:
Calculate the slope m of AB using the slope formula
m = 
with (x₁, y₁ ) = A(6, 2) and (x₂, y₂ ) = B(- 3, 2)
m =
=
= 0
A line with a slope of zero is a horizontal line, parallel to the x- axis.
Thus a line perpendicular to AB is a vertical line parallel to the y- axis.
The slope of a vertical line is undefined