Sources of data In the folldwing table, indicate whether the researcher in the scenario is collecting experimental data or observational data. Scenario Experimental Data Observational Data
A sociologist conducts interviews with former protestors and activists in order to study the struggles of the civil rights movement.
An oncologist randomly assigns rats into two groups, giving one group a new drug intended to fight cancer and giving the other group a placebo, in order to study the effects of the new drug.
A medical doctor randomly assigns individuals into two groups, giving one group a new drug to reduce blood pressure and the other group a placebo, in order to study the effects of the new drug.
The issue of reverse causality is more likely to be present in data sets than in data sets.

Verizon communications, inc., provides the following footnote relating to its leasing activities in its 10-k report. the aggregate minimum rental commitments under noncancelable leases for the periods shown at december 31, 2010, are as follows: years (dollars in millions) capital leases operatingleases 2011 $97 $1,898 2012 74 1,720 2013 70 1,471 2014 54 1,255 2015 42 1,012 thereafter 81 5,277 total minimum 418 $ 12,633 rental commitments less interest and (86) executory costs present value of 332 minimum lease payments less current (75) installments long-term obligation $257 at december 31, 2010 (a) confirm that verizon capitalized its capital leases using a rate of 7.4 %. (b) compute the present value of verizon's operating leases, assuming an 7.4% discount rate and rounding the remaining lease term to 3 decimal places. (use a financial calculator or excel to compute. do not round until your final answers. round each answer to the nearest whole number.)