Question

your company takes orders over the phone. the companys average call time is 4.6 minutes. the graph below shows 4 calls and the difference between the call time and the companys average call time. for these 4 calls, what is the mean difference between the call times and the companys average call time, rounded to the nearest 0.1 minute? (note: a negative difference indicates the call is shorter than the average.) difference between call time and company average call time (negative values indicate calls shorter than company average.) minutes call 3 call 4 call 1 call 2 -2.32 -1.55 4.79 0.68

Explanation:

Step1: Recall the formula for the mean

The mean of a set of numbers $x_1,x_2,x_3,x_4$ is $\bar{x}=\frac{x_1 + x_2+x_3+x_4}{n}$, where $n = 4$ in this case. Here, $x_1=-2.32$, $x_2=-1.55$, $x_3 = 4.79$, $x_4=0.68$.

Step2: Calculate the sum of the differences

$x_1 + x_2+x_3+x_4=-2.32+( - 1.55)+4.79 + 0.68=-2.32-1.55 + 4.79+0.68=1.6$.

Step3: Calculate the mean

The mean $\bar{x}=\frac{1.6}{4}=0.4$.

Answer:

$0.4$