Answer:
By growing a sample of 10 gardenia bushes in the shade and similarly 10 in full sun.
Explanation:
For getting a representative result, the experiment must be done in two different circumstances so that the final results of the two conditions can be compared and condition for better result can be determined.
So, Perry must grow a sample of 10 gardenia bushes in shade and the same number of gardenia bushes i.e. 10 in the full sun. After the plants flower there will be a clear difference in the flowering of both the sample of plants because gardenia bushes flower will in shade than in full sun. So, the average number of flowers will be greater in the shade than in full sun.