Answer:
Confidence interval: (21.9, 32.9).
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 = 26 - 1 = 25
98% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 25 degrees of freedom(y-axis) and a confidence level of . So we have T = 2.485
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 27.4 - 5.5 = 21.9 hours
The upper end of the interval is the sample mean added to M. So it is 27.4 + 5.5 = 32.9 hours
Confidence interval: (21.9, 32.9).
Answer:
y = -4
x = 3
Step-by-step explanation:
Let's first explain when x = 0
Find where x = 0 on the graph. We are finding what the y-value would be. Trace down the y-axis along the vertical line x = 0. Where does the line intersect the y-axis when x = 0? The answer would be -4
The y-intercept is -4, and the x-value for this is 0, of course. So the correct answer for when x = 0 would be y = -4.
Next, we are told to find x when y = -2. Find where y = -2. Now, staying at y = -2, go horizontally along the x-axis at y = -2 until you reach the line. Boom! You should have connected up with the line at around x = 3. Therefore, when y = -2, x = 3
Answer:
x=19º
x+9=28º
7x=133º
Step-by-step explanation:
x+9+x+7x=180
9x+9=180
9x=180-9
9x=171
x=19
Step-by-step explanation:
distance between (12.-7) and (-3, -7)
=12+3
=15 units