The line graph below shows the number of complaints received by the complaints department of a single airline over a six-month period in 2009.
The line graph compares the number of complaints made to an airline’s complaint department through three different channels—personal delivery, telephone, and fax or email—during the first half of 2009. Overall, spoken complaints (in person and by telephone) increased notably over the period, while written complaints (fax and email) declined steadily. Face-to-face complaints showed the most…