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:
99% confidence interval for the true mean difference between the mean amount of mail-order purchases and the mean amount of internet purchases is [$(-31.82) , $12.02].
Step-by-step explanation:
We are given that a random sample of 16 sales receipts for mail-order sales results in a mean sale amount of $74.50 with a standard deviation of $17.25.
A random sample of 9 sales receipts for internet sales results in a mean sale amount of $84.40 with a standard deviation of $21.25.
The pivotal quantity that will be used for constructing 99% confidence interval for true mean difference is given by;
P.Q. =
~
where,
= sample mean for mail-order sales = $74.50
= sample mean for internet sales = $84.40
= sample standard deviation for mail-order purchases = $17.25
= sample standard deviation for internet purchases = $21.25
= sample of sales receipts for mail-order purchases = 16
= sample of sales receipts for internet purchases = 9
Also,
=
= 18.74
The true mean difference between the mean amount of mail-order purchases and the mean amount of internet purchases is represented by (
).
Now, 99% confidence interval for (
) is given by;
=
Here, the critical value of t at 0.5% level of significance and 23 degrees of freedom is given as 2.807.
=
= [$-31.82 , $12.02]
Hence, 99% confidence interval for the true mean difference between the mean amount of mail-order purchases and the mean amount of internet purchases is [$(-31.82) , $12.02].
Answer:
The answer here would be false
Step-by-step explanation: