Question 9

Analysis of the cellular structure of Chewbacca (a Wookie) showed that most of the basic cellular and molecular processes are the same between Wookies and humans, much as they are the same between humans and other closely related organisms. Many proteins are highly conserved and basic cellular metabolism is maintained. Interestingly, one new organelle is present, which researchers named the Wookiesome. Many of the proteins found within the Wookiesome have the eight amino acid sequence “HARRIEST”. You make a hypothesis that this region is important for organelle import.

(A) Design an experiment to indicate if “HARRIEST” is necessary for organelle import.

(B) Design an experiment to indicate if “HARRIEST” is sufficient for organelle import.

(C) Explain how it is possible that the sequence could be necessary but not sufficient.

4. Explain how it is possible that the sequence could be sufficient but not necessary

A.) Suppose that we run the exact same experiment 100 times and find a statistically significant difference 30 times out of 100 using an alpha level of .05. What is the best estimate of our statistical power?

a) a difference between means is very likely to be detected

b) the significance level set by the researcher must be high

c) the probability of type I error is very high

d) Your study will likely be inconclusive

B) A researcher believes that dogs can smell fear, so he conducts an experiment with blindfolded dogs next to a person who is watching either a scary or a funny movie. What is the null hypothesis (Ho)?

a) dogs can smell fear

b) dogs cannot smell fear

c) that the probability value will be below 0.05

d) that there will be a statistically significant result

A.) Suppose that we run the exact same experiment 100 times and find a statistically significant difference 30 times out of 100 using an alpha level of .05. What is the best estimate of our statistical power?

a) a difference between means is very likely to be detected

b) the significance level set by the researcher must be high

c) the probability of type I error is very high

d) Your study will likely be inconclusive

B) A researcher believes that dogs can smell fear, so he conducts an experiment with blindfolded dogs next to a person who is watching either a scary or a funny movie. What is the null hypothesis (Ho)?

a) dogs can smell fear

b) dogs cannot smell fear

c) that the probability value will be below 0.05

d) that there will be a statistically significant result

Context: An experiment investigated the reaction between crystal violet (a purple colored dye) and hydroxide ion using spectrophotometry. The collected data was then analayzed to determine the concentration dependence of the speed of the reaction which was used to establish the rate law of the reaction which was used to determine the value of its rate constant. Since the reaction of interest involved two charged species, an aqueous solution of NaCl was used alongside an aqueous solution of sodium hydroxide to enforce the same electrical nature of the reaction medium in the determination of reaction order. Since NaCl is not involved in the reaction, it is called an intert electrolyte used to maintain the same electrical nature of the medium when [OH^-] is varied.

Question: What was the role of sodium chloride in the experiment and what kind of problem(s) would be encountered if sodium chloride was left out?

1.A bomb calorimeter, or a constant volume calorimeter, is a device often used to determine the heat of combustion of fuels and the energy content of foods. In an experiment, a 0.3807 g sample of 1,6-hexanediol (C6H14O2) is burned completely in a bomb calorimeter. The calorimeter is surrounded by 1.139×103 g of water. During the combustion the temperature increases from 25.30 to 27.59 °C. The heat capacity of water is 4.184 J g-1°C-1. The heat capacity of the calorimeter was determined in a previous experiment to be 760.0 J/°C. Assuming that no energy is lost to the surroundings, calculate the molar heat of combustion of 1,6-hexanediol based on these data. C6H14O2(s) + (17/2) O2(g) 7 H2O(l) + 6 CO2(g) + Energy Molar Heat of Combustion = ? kJ/mol

1. Consider an infinite sequence of independent experiments, where in each experiment we take k balls, labeled 1 to k, and randomly place them into k slots, also labeled 1 to k, so that there is exactly one ball in each slot. For the nth experiment, let Xn be the number of balls whose label matches the slot label of the slot into which it is placed. So X1, X2, . . . is an infinite sequence of independent and identically distributed random variables.

   1. (a) Find the expected value and variance of Xn.

   2. (b) Use the central limit theorem to approximate the probability that in the first 40 experiments

      the total number of balls whose label matches their slot label is greater than 40 (this means find

      an approximation to P (?40 Xn > 40) using the central limit theorem.)n=1

The following question is based on the lifetime of muon lab.

(i) The muons whose decays we observe are born outside the detector and therefore spend some (unknown)
portion of their lifetime outside the detector. So, we never measure the actual lifetime of any muon.
Yet, we claim we are measuring the lifetime of muons. How can this be? In addition to this, Why do the lifetimes of positive and negative muons differ?

(ii)The timeout interval for the experiment was found to be 20.02 microseconds. What does the timeout interval of the FPGA imply about the maximum time between signal pulses when conducting the lab? Please explain this part in detail.

(iii) Explain the behaviour of the muon rate reported by the software as the discriminator threshold and
HV setting are varied. (Note that during the experiment, the muon rate decreased for both) Why is this?

a couple intends to have three children. assume (for some reason) that having a boy or a girl are not equally likely events, and that p(boy)=.4 and p(girl)=.6 for each delivery also assume the births are independent of each other

(a. what is the sample space of this experiment? Use a tree diagram and label the branches with their corresponding probabilities. Then make a table including all outcomes from the experiment with their associated probabilities.

(b. Find the probability that the couple has exactly two girls.

(C. Find the probability that the couple has at least one boy

Let X represent the discrete random variable corresponding to the number of girls the couple has. What is the probability distribution of the random variable X? Hint: Take your table above, summarize it, and list "sideways"

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?