A student decides to conduct an investigation to determine the boiling points of water and ethanol. The student will heat samples of water and ethanol, and measure the temperature at which the samples boil. The student will conduct the investigation three times. Which aspect is missing from the experimental design? (1 point)

deciding on the
• number of trials to perform
•determining what data to collect
deciding on the appropriate equipment
determining the procedure

deciding on the appropriate control variables