Final answer:
Venetta's mistake is not applying the correct conversion factor; to convert 5 mi/h to km/h, she should multiply by 1.6 to get 8 km/h.
Step-by-step explanation:
The error Venetta makes is not completing the unit conversion correctly. To convert 5 mi/h to km/h, one should multiply the speed in miles per hour by the conversion factor that relates miles to kilometers. Since 1 mile is approximately equivalent to 1.6 kilometers, the correct calculation should be 5 mi/h × 1.6 km/mi, which results in 8 km/h. Venetta incorrectly multiplies by 1 mile instead of 1.6 kilometers per mile.