Determine whether the given description corresponds to an experiment or observational study. a. A stock analyst selects a stock from a group of twenty for investment by choosing the stock with the greatest earnings per share reported for the last quarter. b. A marketing firm does a survey to find out how many people use a product. Of the one hundred people contacted, fifteen said they use the product. c. A political pollster reports that his candidate has a 10% lead in the polls with 10% undecided. d. A doctor gives a new medication to half of his patients with the flu and a placebo to the other half of his patients with the flu.

Statement reason 1. δabc is similar to δced. given 2. 3. definition of slope 4. slope of slope of definition of slope 5. slope of × slope of multiplying the slopes 6. slope of × slope of substitution property of equality 7. slope of × slope of simplifying the right side the table contains the proof of the relationship between the slopes of two perpendicular lines. what is the reason for statement 2? a. parallel line segments that meet a common perpendicular line are proportional in length. b. the lengths of vertical and horizontal sides in congruent triangles are in a common ratio. c. trigonometric identities determine the lengths of the legs in a right triangle. d. corresponding side lengths in similar triangles are proportional in length.