Does aspirin cure headaches? A study enrolled 100 students who had frequent headaches to particpate in a study to examine the effets of aspirin on their headaches. The students were instructed to take aspirin when they had a headache and to report whether there was a substantial relief from the headache pain within an hour.

a) explain why this study is biased

b) explain how would you change the study to remove the bias

Randomization- : Diagram the aspirin experiment. - draw a diagram that describes the experiement you suggested in part b above. (Intro to Stats- chapter 3, section 3.2 Design of Experiments, 3.19 pg175)

To your question: You have to answer part b as indicated above "b)explain how you would change the study to remove the bias" then draw a diagram that describes the experiment you suggested.

What four different methods are frequently used to collect data?
14. True or false? Randomization is used to increase bias in a study. ?
15. What are three key elements of a well-designed experiment?
16. What problem can be introduced if confounding variables are present in a study?
17. Why is the validity of an experiment important?
18. What is the purpose of using blinding in a study?
19. You are asked to select a random sample of 10 students from the class. What must be done before anything else to start the process?
20. Identify the sampling technique. As part of a quality assurance program, every seventh car produced on an assembly line is subjected to additional evaluation.
21. Understanding the reasons. Why is simulation sometimes necessary when collecting data?

1. A animal behaviorist wants to know how exercise affects behavior of aggressive dogs. She finds a sample of 30 aggressive dogs and randomly divides them into three groups. Over one week, one group is exercised for 20 minute per day, one for one hour per day, and one for 2 hours per day. The number of aggressive behaviors (lunging, biting, snarling, etc.) is recorded for the dogs in each group.

1. State the population(s) of interest.

2. Identify the parameter(s) of interest.

3. Is this an observational study or a controlled experiment? Explain.

4. What type of analysis does this anticipate?

5. If applicable, identify one problem with the sampling scheme and explain how this would bias the results of the experiment. Otherwise, explain why you think the sampling is well don

The idea is about genetic testing not about getting a specific answer.

In a genetics experiment of a pathway, loss of function in gene X or gene Y causes a blue phenotype, and loss of function in gene Z causes a green phenotype.

What experiments could you use to find the order and regulatory relationships of all the genes? Assume you have all the types of alleles you would want and explain what you would observe in your experiment if gene X --| gene Z --| gene Y.

You then find a loss of function mutant called mutant M that expresses a green phenotype. How would you figure out using only a classic genetic test if mutant M is a new allele of gene Z or if it is an allele of a new gene?

1) You are a research scientist studying a novel enzyme X, and you want to characterize this new enzyme. You measure the velocity of the reaction with different substrate concentrations and get the following data:

[S] (mM)	Initial Velocity (mmol/min)
3.0	10.4
5.0	14.5
10.0	22.5
30.0	33.8
90.0	40.5

a) Graph the above data. From the graph, estimate KM and Vmax (Michaelis-Menten Plot)

b) Use Lineweaver-Burk plot to calculate Km and Vmax. Show all equations and calculations.

c) You decide to do this experiment again, but this time with only one third of the enzyme X concentration used in the first experiment. Draw a new graph on the same graph that you did the first graph on. Estimate Km and Vmax from the new graph.

Question:1 In the introduction of this experiment, there are several factors that are discussed as having an impact upon the rate of a reaction. Pick one of these factors and come up with an original idea (not from the experiment or lecture) where the factor plays a role in the rate at which a chemical reaction occurs. Be sure to explain how and why your idea affects the rate of the reaction chosen. For example: if you increase the surface area of a piece of coal by crushing it up, it will react with oxygen (burn) much more rapidly. This illustrates the relationship between surface area and reaction rate. Question:2 There is a general rule of thumb that the rate of an observable chemical reaction doubles with every 10oC increase in temperature. How much would the rate of a chemical reaction change if the temperature were to increase by 80.0oC? Be sure to show your work.

I have a lab assignment that I'm not sure how to do. The experiment is a cart moving 60cm distance and there is a fan on top of it making it have a mass of .56kg. Every trial there is 100g added to the cart. For this part, the time is kept the same.

1. If the force provided by the fan was the same for each run and we have chosen the same time interval, how does the impulse from that force compare from one run to another? Make sure that you use the definition of impulse ( J=Favg∆t) in your explanation.

2. Will the change in momentum the same (or nearly the same) for each of the runs?

Extra questions not related to experiment.

1. What do you conclude about the relationship of work and changes in kinetic energy?

2. What do you conclude about the relationship of impulse and changes in momentum?

Wrap up question 1: You hold a “Top” piece of charged tape near an uncharged soda can. Describe the behavior of the tape. Would the behavior be different if you used a “Bottom” piece of tape instead? Explain.

Wrap up question 2: Suppose there exists a third type of charge in addition to the two types we associate with glass and plastic. Call this third type X charge. What experiment(s) could you use to test whether an object has X charge? State clearly how the outcome(s) of the experiment(s) would be interpreted.

Wrap up question 3: A positively charged electroscope has separated leaves. Describe what will happen if you bring a negatively charged rod near, but not touching, the top of the electroscope.

1. Consider the following situation. With the power supply off, the current limit one-half of a turn and the voltage knob completely counterclockwise, a coil is connected to it. A secondary coil is placed just in front and connected it to a galvanometer. If you gently increase the voltage of power supply, explain what you would observe in the galvanometer. Would the needle deflect? Why?

2. If the secondary coil is moved away from the primary coil, would the deflection of the needle be larger, smaller, or the same? Explain!

3. In this experiment, you moved the bar magnet closer to or away from the coil while keeping the coil stationary. How would the result change if the moved the coil while the bar magnet is kept at rest? Explain!

If you move both the bar magnet and the coil, how would this motion change the result you observed in this experiment. Explain!

Scenario B: Consider the following experiment. Each participant interacted for an hour with another person who was actually a research confederate (an actor working for the researcher). The confederate either presented herself as similar or dissimilar to the participant. After this interaction, both persons agreed to return 1 week later for another session with each other. When the real participants returned, they were falsely informed that the person they had met the week before had died. The researchers then compared how long the participant spent viewing a picture of the “deceased” depending on whether the person had presented as similar or dissimilar to them. The participant was never told that the reported death was untrue. Write a hypothesis that is tested in this study. Discuss the ethical issues raised in the experiment. What would you recommend the experimenters do to protect the participants and minimize risk of harm?