Question

biology students carried out an experiment to determine if a certain fertilizer increased growth (height) in plants. the students selected 4 different types of plants and planted 10 seeds of each type: 5 treated with fertilizer and 5 not treated with fertilizer. all other conditions were identical. the students recorded the collected data in this table.

plant height (cm) after 120 days

	castor bean	okra	radish	tomato
90	85	75	70	15	10	150	140
86	90	80	80	20	16	145	130
83	80	75	70	25	20	155	135
80	75	75	65	20	15	160	120
75	75	75	70	20	20	165	125

which type of plant exhibited the greatest increase in height when treated with fertilizer?
a. castor bean
b. okra
c. radish
d. tomato

Explanation:

Step1: Calculate increase for Castor bean

Find the average height of fertilized and non - fertilized Castor bean plants. Fertilized: $\frac{90 + 86+83 + 80+75}{5}=82.8$, non - fertilized: $\frac{85 + 90+80+75+75}{5}=81$. Increase is $82.8 - 81 = 1.8$.

Step2: Calculate increase for Okra

Fertilized Okra average height: $\frac{75+80 + 75+78+75}{5}=76.6$, non - fertilized: $\frac{70+80+80+85+70}{5}=77$. Increase is $76.6 - 77=- 0.4$.

Step3: Calculate increase for Radish

Fertilized Radish average height: $\frac{15+20+25+20+20}{5}=20$, non - fertilized: $\frac{10+16+20+15+20}{5}=16.2$. Increase is $20 - 16.2 = 3.8$.

Step4: Calculate increase for Tomato

Fertilized Tomato average height: $\frac{150+145+155+160+165}{5}=155$, non - fertilized: $\frac{140+130+135+120+125}{5}=130$. Increase is $155 - 130 = 25$.

Answer:

D. Tomato