Question: (Extra Credit – 7 pt – dataset in Excel file) Bromeliads are tropical fiord ring plants. Many are epiphytes that attach to trees and obtain moisture and nutrients from air and rain. Their leaf bases fl rin cups that collect water and arc home to the larvae of many insects. In an experiment in Costa Rica, scientists studied hether added nitrogen increases the productivity of bromeliad plants. Bromeliads were randomly assigned to nitrogen or control groups. Here are the data on the number of new leaves produced over a 7-month period.

Control 11 13 16 15 15 11 12

Nitrogen 15 14 15 16 17 18 17 13

Is there evidence that adding nitrogen increases the mean number of new leaves formed?

a. (1) State the (Ho) and alternative hypotheses (Ha)

b. (2) Calculate the test statistic

c. (1) What are the degrees of freedom you should use to find your p-value?

d. (1) What are the t-values that bracket your test statistic?

a. (1) Find the p-value (range it falls between)

f. (1) State your conclusion in terms of the problem using 5% significance.