Did I answer these correctly? Too many true answers based on my research. Uncertain about 1, 2 and 2

1) __T__ An association not explained by bias, chance, confounding means an association is causal.

2) __T__ The connection among intention, decision, behavior, and outcome is not always clear.

3) __T__ Positive predictive value is more influenced by the sensitivity than the specificity of the screening test.

4) __T__ Specificity answers the question: “Of all individuals that were free of disease A, what proportion tested negative?”

5) __T__ Successful treatment programs that shorten the duration of a disease primarily affect the prevalence of the disease rather than the incidence rate.

6) __T_ The preclinical phase of disease lasts from the biological onset to the development of symptoms.

7) __T__ Incidence rate is a true rate because the denominator is defined in terms of person-time whereas cumulative incidence is a proportion.

8) __T__ A clinical trial entails comparing a group of patients treated with a test treatment to a comparable group of patients receiving a control treatment.

9) __F__ Experimental study designs have lower validity than cohort studies.

10) _T__ A “gold standard” is used to determine whether a screening test is effective.

In my lab, we conducted an experiment to demonstrate both Hess' Law and the fundamentals of enthalpy via the formation of magnesium oxide. In this experiment, 2 specific sub-reactions were conducted:

1. MgO(s) + 2HCl(aq) > MgCl₂(aq) + H₂O(l)

2. Mg(s) + 2HCl(aq) > MgCl₂(aq) + H₂(g)

In these two reactions, different concentrations of HCl were used: the first reaction called for 100mL of 6M HCl, while the second reaction called for 120mL of 6M HCl.

The lab manual says that this is an important distinction. Why is it important that two different concentrations of hydrochloric acid were used for each reaction?

"Make a tree diagram to determine the theoretical probability for this experiment: Spin the arrows (not shown) on each of the following three spinners, and note the color where the arrow lands on each spinner. Spinner 1 is divided into two equal sectors, labeled “Red” and “Blue.” Spinner 2 is first divided into two equal sectors. The left is labeled “Green.” The right is then divided into two equal sectors, labeled “Red” and “Blue.” Spinner 3 is divided into three equal sectors, labeled “Red,” “Blue,” and “Green.” Give the sample space for the experiment and the probability of each outcome. What is the probability of getting at least 1 red? What is the probability of getting at least 1 blue?"

Part A) 525mL of 1.50M NaCl is added to a beaker containing 378mL of 2.22M AgNO3, resulting in the formation of AgCl precipitate. What is the limiting reactant?

NaCl

AgNO3

AgCl

NaNO3

Part B) How many grams of K₂SO₄ are in 250mL of 0.11 M K₂SO₄ solution?

___ g K₂SO₄

Part C) The reaction of magnesium nitride and water is shown below:

Mg₃N₂ + 3H₂O --> 2NH₃ + 3MgO

During a lab experiment, 3.82 g magnesium nitride and 7.73 g water are placed in a reaction flask.

At the end of the experiment, the amount of magnesium oxide produced is 3.60 g.

What is the percent yield of the reaction?

Design an experiment to find the relationship between the electric force between the two spheres and the distance between them. In the space below, describe your experiment, including:

• What quantity did you vary?
• What quantities did you hold constant?
• What quantity did you measure?
• Which quantities did you plot on your graph, and on which axes?
• Which Curve Fit gives the best fit for the data?

Describe your process and the relationship you found. In particular, note where the data deviated the most from your curve fit. Why did the data deviate from your curve fit at those locations?

Put the argument into standard form, and then diagram it

It is very unlikely that research using animals will be unnecessary or poorly done. Before an experiment using a vertebrate animal is carried out, the protocol for that experiment must be reviewed by an institutional committee that includes a veterinarian and a member of the public, and during the research the animal’s health and care are monitored regularly. Researchers need healthy animals for study in science and medicine, because unhealthy animals could lead to erroneous results. This is a powerful incentive for scientists to make certain that any animals they use are healthy and well-nourished. Furthermore, research involving animals is expensive, and because funding is limited in science, only highquality research is able to compete effectively for support.

Put the arguments into standard form, and then diagram it

It is very unlikely that research using animals will be unnecessary or poorly done. Before an experiment using a vertebrate animal is carried out, the protocol for that experiment must be reviewed by an institutional committee that includes a veterinarian and a member of the public, and during the research the animal’s health and care are monitored regularly. Researchers need healthy animals for study in science and medicine, because unhealthy animals could lead to erroneous results. This is a powerful incentive for scientists to make certain that any animals they use are healthy and well-nourished. Furthermore, research involving animals is expensive, and because funding is limited in science, only highquality research is able to compete effectively for support

Put the arguments into standard form, and then diagram it

It is very unlikely that research using animals will be unnecessary or poorly done. Before an experiment using a vertebrate animal is carried out, the protocol for that experiment must be reviewed by an institutional committee that includes a veterinarian and a member of the public, and during the research the animal’s health and care are monitored regularly. Researchers need healthy animals for study in science and medicine, because unhealthy animals could lead to erroneous results. This is a powerful incentive for scientists to make certain that any animals they use are healthy and well-nourished. Furthermore, research involving animals is expensive, and because funding is limited in science, only highquality research is able to compete effectively for support

You wish to compare four treatments for effectiveness in preventing flu: (1) a flu vaccine, (2) 1 gram of vitamin C per day, (3) an Echinacea pill, (4) a turmeric curcumin complex pill, and (5) a placebo taken daily. (A placebo is a dummy pill which contains no active ingredient and should have no physical effect.)

In clinical experiments involving people, it is strongly recommended that a placebo be included among the treatments. Explain why.

What is an appropriate response variable?

Suppose that 1000 volunteer subjects are available for the study. Draw a diagram showing a

design of your experiment. Clearly indicate where randomization, replication and control are applied in the experiment.