Question

mathematics 7 - 7 - full year
6 - 2: mathxl for school: additional practice
due
feb 5 - 11:45 pm
part 1 of 3
the following dot plots show the amount of time it takes each person, in a random sample, to complete two similar problems. what is the mean time for each problem? make a comparative inference based on the mean values.
problem 1
problem 2
24 25 26 27 28 29 30 31 32 33 34
time (minutes)
24 25 26 27 28 29 30 31 32 33 34
time (minutes)
the mean time for problem 1 is
minutes.
(type an integer or a decimal.)
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question 2 of 6 back next

Explanation:

2: contribution = 26*2 = 52

• Time = 27, number of dots = 3: contribution = 27*3 = 81
• Time = 28, number of dots = 4: contribution = 28*4 = 112
• Time = 29, number of dots = 3: contribution = 29*3 = 87
• Time = 30, number of dots = 2: contribution = 30*2 = 60
• Time = 33, number of dots = 1: contribution = 33*1 = 33

Total time = 52+81 + 112+87+60+33 = 425

Number of data points = 2 + 3+4 + 3+2 + 1 = 15

Mean = 425/15≈28.33. But the problem says "type an integer or a decimal". So maybe the answer is approximately 28.33, but let's check again. Wait, maybe I miscounted the number of dots. Let's count the number of dots for each time:

Wait, maybe the dots are:

• 26: 2
• 27: 3
• 28: 4
• 29: 3
• 30: 2
• 33: 1

Yes, that's 2+3+4+3+2+1 = 15.

So mean time for Problem 1 is \(425\div15\approx28.33\) minutes. But maybe the problem expects a different calculation. Wait, maybe the last dot is at 33, but maybe I made a mistake in the time values. Alternatively, maybe the time at 33 is 30, but no, the x - axis is 33.

Wait, perhaps the correct mean is 28.33, but let's check with another approach.

Wait, maybe the number of dots is different. Let's look at the dot plot again. The dot plot for Problem 1:

• At 26: 2 dots
• At 27: 3 dots
• At 28: 4 dots
• At 29: 3 dots
• At 30: 2 dots
• At 33: 1 dot

Total dots: 2+3+4+3+2+1 = 15.

Total time: 262 + 273 + 284 + 293 + 302 + 331 = 52+81+112+87+60+33 = 425.

Mean: 425/15 = 28.333...≈28.33.

But maybe the problem has a different set of dots. Wait, maybe the dot at 33 is a mistake, and it's 30? No, the problem shows a dot at 33.

Alternatively, maybe I misread the dot plot. Let's assume that the dot at 33 is actually at 30, but that's not correct.

Wait, maybe the correct mean is 28.33, so we can write it as 28.33 or as a fraction \( \frac{425}{15}=\frac{85}{3}\approx28.33\).

Answer:

\(28.33\) (or \(\frac{85}{3}\) or approximately 28.33)