Answer:
The 95% confidence interval for the average number of units that students in their college are enrolled in is between 11.7 and 12.5 units.
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution 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 = 45 - 1 = 44
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 44 degrees of freedom(y-axis) and a confidence level of
. So we have T = 2
The margin of error is:

In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 12.1 - 0.4 = 11.7 units
The upper end of the interval is the sample mean added to M. So it is 12.1 + 0.4 = 12.5 units
The 95% confidence interval for the average number of units that students in their college are enrolled in is between 11.7 and 12.5 units.
Answer:
D. One
Step-by-step explanation:
A parallelogram will have two sets of equal sides. Since we have that fact, all we need to know are the angles.
A quadrilateral will have a total of 360° in its angles. If only one angle is equal to 90°, then we can do <u>the math</u> to figure out that all the others must be 90° as well. A rectangle is a parallelogram with the opposite sides being parallel and all the angles being 90°. This then answers the question.
"<u>The Math</u>"
-> Keep in mind there will be four angles
-> Once we subtract the first angle of 90°, we will have three angles left. Hence why we divide by 3.
360° - 90° = 270°
270° / 3 = 90° ✓
Answer:
129
Step-by-step explanation: