Answer:
The 99% confidence interval for the population mean reduction in anxiety was (1.2, 8.6).
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 = 27 - 1 = 26
99% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 26 degrees of freedom(y-axis) and a confidence level of . So we have T = 2.7787.
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 4.9 - 3.7 = 1.2.
The upper end of the interval is the sample mean added to M. So it is 4.9 + 3.7 = 8.6.
The 99% confidence interval for the population mean reduction in anxiety was (1.2, 8.6).
The ratio of the length of the room to its area is
Answer:
He missed 10 questions and got 30 right
Step-by-step explanation:
So we could do 0.75 times 40 and we would get 30
So he got 30 questions right which isn't too bad
Answer:
20 out of 28 games.
Step-by-step explanation:
28 divided by 7 is 4.
5 times 4 is 20.
20 out of 28 games.
(This is simple math honestly.)
Answer:
Step-by-step explanation:
x² = 19x + 12
⇔ x² - 19x - 12 = 0
Calculating the discriminant :
b² - 4ac = (-19)² - 4×1×(-12) = 409
The discriminant is positive ,then the equation has two solutions.