Question

Researchers measured the data speeds for a particular smartphone carrier at 50 airports. The highest speed measured was 73.4 Mbps. The complete list of 50 data speeds has a mean of x=16.23 Mbps and a standard deviation of s=18.01 Mbps.

Answer 1

Part A

The difference is given by

73.4-16.23=57.17 Mbps

Part B

we know that

s=18.01 Mbps

Divide 57.17 Mbps by 18.01 Mbps

so

57.17/18.01=3.17 standard deviations

Part C

The answer must be equal to the number of standard deviations (Part B)

z=3.17

Part D

Remember that

For X=57.17 Mbps -----------> z=3.17

so

For Z between -2 and 2

the answer is significantly low