Question

the dot plot shows the number of hours, rounded to the nearest half hour, it took alexis to box braid the hair of 30 customers. alexis says that the mean time is greater than 7 hours. is she correct? use the drop - down menus to explain. box braids click the arrows to choose an answer from each menu. the data in the dot plot are choose... and have a median of choose... hours.

Explanation:

Step1: Calculate sum of data values

Let's count the number of dots at each value. At 2, assume 2 dots; at 3, 2 dots; at 4, 3 dots; at 5, 5 dots; at 6, 7 dots; at 7, 8 dots; at 8, 4 dots; at 9, 2 dots; at 10, 1 dot. The sum is \(2\times2 + 3\times2+4\times3 + 5\times5+6\times7+7\times8+8\times4+9\times2+10\times1=4 + 6+12 + 25+42+56+32+18+10 = 205\).

Step2: Calculate the mean

The mean \(\bar{x}=\frac{\text{Sum of data values}}{\text{Number of data - points}}\). There are \(2 + 2+3 + 5+7+8+4+2+1=30\) data - points. So, \(\bar{x}=\frac{205}{30}\approx6.83\) hours.

Answer:

No, Alexis is not correct. The mean time is approximately \(6.83\) hours which is less than 7 hours.