And we measure the height of my plants over a 3-week experimental period and obtain the following data for the final week in centimeters 15, 18, 21, 19, 20

Calculate that final average height for this group of plants around your answer to one decimal place

18.6 cm
6.0 cm
4.2 cm
13.3 cm

To calculate the average height, you need to sum all the measurements and then divide by the number of measurements.

Sum of measurements: 15 + 18 + 21 + 19 + 20 = 93 cm
Number of measurements: 5

Average height = Sum of measurements / Number of measurements
Average height = 93 cm / 5 = 18.6 cm

Therefore, the final average height for this group of plants is 18.6 cm.