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A foot doctor is investigating a new orthopedic insert for people who suffer from intense heel pain. He wants to see if the new orthopedic insert works better than the current orthopedic on the market. He takes a random sample of 10 patients from his practice and want to give them one of the new orthopedic to try on one foot and one of the current orthopedic to try on their other foot (he will randomly decide which foot gets the new orthopedic by flipping a coin…heads and it goes on the right foot, tails and it goes on the left foot.) He will measure and compare the difference in their heel pain for each of their feet. What type of experimental design is he using?

A laser pointer used in a lecture hall emits light at 650 nm. What is the frequency of this radiation? Given the speed of light (c) is 2.99 x 108m/sec and c = λν and 1 nm = 1.0 x 10-9 m.

An herbalist (a person that studies herbs) conducted a study to investigate whether there is a difference between the number of basil leaves during the growing season for basil plants when one of two types of fertilizers is applied to the soil. The herbalist randomly assigned 90 basil plants from a local nursery to receive one of the two fertilizers just before the growing season, with 45 receiving an organic fertilizer and 45 receiving a conventional fertilizer. An employee of the nursery, who was not aware of each basil plant’s assigned fertilizer, counted the number of basil leaves observed during the growing season on each basil plant. The results of the study are shown in the following boxplots.   a)  Based on the boxplots, write a few sentences comparing the distributions of the number of basil leaves during the growing season for the basil plants that received the organic fertilizer and the basil plants that received the conventional fertilizer. b)  Can the findings of this study be generalized to all basil plants? Explain why or why not. 

Which ion Mg2+, Cl-, Ca2+, or I- has the smallest ionic radius?

In balancing the equation for the following reaction W CH4(g) + X Cl2(g) → Y CCl4(l) + Z HCl(g), what are the values for the coefficients W, X, Y, and Z?

In a rainbow, which color has the largest wavelength?

What generalizations can we make about anions in comparison to their parent atom?

Industrial work was dangerous and difficult

Many people treat a condition called “dry eye” with a eye drops.  An eye doctor plans to conduct a study to investigate the following claim made in a recent report. For people with a condition called “dry eye”, there is a difference between the proportion cured by using Eye Drops A and the proportion cured by using Eye Drops B. The doctor will randomly assign 200 volunteers with the eye condition to use one of two eye drops, with 100 assigned to use Eye Drops A  each day and the remaining 100 assigned to use Eye Drops B each day. The doctor will record the number of people cured after six months for each eye drop. (a) Describe the benefit of randomly assigning the type of eye drops to the volunteers. (b) Describe a process that can be used to randomly assign the 200 volunteers to the two eye drops.

New electric lights and powerful machinery allowed factories to run twenty-four hours a day, seven days a week.