- For each data category, the following bars are shown:
- no lizards
- with lizards
- All values are approximate.
- The data for the 4 categories are as follows:
- Day 1:
- no lizards: 85
- with lizards: 85
- Day 10:
- no lizards: 62
- with lizards: 32
- Day 20:
- no lizards: 51
- with lizards: 27
- Day 30:
- no lizards: 43
- with lizards: 23
- Day 1:
To investigate the effect of lizard predation on spider populations, a student in a biology class placed spiders in two enclosures, one with lizards and one without, and tracked the number of spiders in the enclosures for 30 days. The student concluded that the reduction in the spider population count in the enclosure with lizards by day 30 was entirely attributable to the presence of the lizards.
Which choice best describes data from the graph that weaken the student’s conclusion?