<u>Answer</u>: No, we do not have sufficient evidence to conclude that the mean call duration, µ, is different from the 2010 mean of 9.4 minutes.
Step-by-step explanation:
As per given , we have
, since is two-tailed so , the test is a two tail test.
Since population standard deviation is unknown, so we use t-test.
Critical value (two-tailed) for significance level of 0.01=
For n =50 , and s= 4.8
Test statistic :
Since test statistic value (-1.18) lies in critical interval (-2.609228, 2.609228), it means the null hypothesis is failed to reject.
We do not have sufficient evidence to conclude that the mean call duration, µ, is different from the 2010 mean of 9.4 minutes.
To make a box and whisker plot, first you write down all of the numbers from least to greatest.
0, 1, 3, 4, 7, 8, 10
The median is 4, so that’s the middle line of the plot.
So now we have:
0, 1, 3, [4,] 7, 8, 10
So next we have to find the 1st and 3rd interquartiles..
0, [1,] 3, [4,] 7, [8,] 10
Those are the next 2 points you put on the plot.
Lastly, the upper and lower extremes. These are the highest and lowest numbers in the data.
[0,] 1, 3, 4, 7, 8, [10]
These are the final points on the plot.
To make the box of a box-and-whisker plot, you plot the 3 Medians of the data: 1, 4, and 8, and connect those to make a box that has a line in the middle at 4.
Next, you plot the upper and lower extremes: 0 and 10, by making “whiskers” that connect to the box. So you draw a line from the extremes to the box.
Answer:
Step-by-step explanation:
Let's Jiri's age be "J" and Pamela's age be "P".
P = 9 + J (Pamela is 9 years older than Jiri.) ... equation 1
P + J = 107 (the sum of their ages is 107) ... equation 2
Put equation 1 into equation 2:
(9+J) + J = 109
9 + 2J = 109
2J = 109 - 9
2J = 100
J = 100/2
J = 50
Therefore, Jiri's age is 50.
Subtract 7 to 28 = 21 then divided by -3 = x= -7