A nonprofit company concerned with the school dropout rates has designed a tutoring program aimed at students between 16 to 18 years old. A national center for educational statistics reported that the high school dropout rate for the year 2000 was %. One school district, who adopted the use of the nonprofit's tutoring program and whose dropout rate has always been very close to the national average, reported in 2004 that of their students dropped out. Is their experience evidence that the tutoring program has been effective?

Panthers and leopards prey on deer in an ecosystem. for unknown reasons, the population of leopards increased drastically. what are the likely effects of this change on the species? 1. more food for panthers and more competition for leopards 2. less food and more competition for panthers 3. fewer deer and more competition for panthers 4. more food for deer and less competition for panthers and leopards 5. more food for leopards and less competition for panthers

The graph shows a trend in an ecosystem over time caused by increased pollution in the region. what can you conclude from the graph? a. there’s lower biodiversity among birds. b. there’s a higher reproductive rate among birds. c. there’s a significant decline in the number of producers. d. other types of animals were unaffected by pollution.

An ecosystem is shown in the illustration. assume that human activities have led to a decrease in the number of eagles. a virus attack on rabbits has led to a decrease in their population in the ecosystem. which two sentences describe likely effects on the ecosystem? 1. there’s an increase in the number of snakes and insects and a decrease in the number of frogs. 2. there’s an increase in the number of snakes and insects, and the storks face increased competition for food. 3. there’s an increase in the number of storks and a decrease in the number of snakes and insects. 4. there’s an increase in the number of frogs and a decrease in the number of storks and insects. 5. there’s a decrease in the number of snakes, insects, and frogs.