Chapter 12.6, Problem 1CYU

a.

To determine

To calculate: the probability that a randomly chosen customer will have used the GPS system more than 20 times

Answer to Problem 1CYU

The probability for customer who have used GPS more than 20 times is $4.7\%$

Explanation of Solution

Given information:

Total number of customers surveyed are 10000.

number of customers who used GPS zero times are 1382, number of customer who used GPS 1 to 5 times are 2350, number of customer who used GPS 6 to 10 times are 2010, number of customer who used GPS 11 to 15 times are 1863, number of customer who used GPS 16 to 20 times are 1925 and the number of customer who used GPS more than 21 times are 470.

Calculation: the probability for a randomly chosen customer who have used GPS more than 20 times can be calculated as,

  $\begin{array}{l}\left(\frac{470}{10000}\right)\times 100\%\\ =0.047\times 100\%\\ =4.7\%\end{array}$

Therefore, the probability for customer who have used GPS more than 20 times is $4.7\%$

b.

To determine

To calculate: the probability that a randomly chosen customer have used the GPS no more than 10 times.

Answer to Problem 1CYU

Theprobability for customer who have used GPS no more than 10 times is $57.42\%$

Explanation of Solution

Given information:

Total number of customers surveyed are 10000.

number of customers who used GPS zero times are 1382, number of customer who used GPS 1 to 5 times are 2350, number of customer who used GPS 6 to 10 times are 2010, number of customer who used GPS 11 to 15 times are 1863, number of customer who used GPS 16 to 20 times are 1925 and the number of customer who used GPS more than 21 times are 470.

Calculation:the probability for customers who have used GPS no more than 10 times can be calculated as,

  $\begin{array}{l}\left(\frac{1382+2350+2010}{10000}\right)\times 100\%\\ =\left(\frac{5742}{10000}\right)\times 100\%\\ =0.5742\times 100\%\\ =57.42\%\end{array}$

Therefore,the probability for customer who have used GPS no more than 10 times is $57.42\%$