In a famous experiment, dating from 1914, Henry Ford introduced a daily wage of $5, which was approximately twice the prevailing wage at the time. The evidence suggests that this policy did indeed pay off in terms of greater effort, lower absenteeism, and other benefits.

Discuss:

1. How is that possible? Which mechanism could possibly lead to this outcome?
2. Do you see any application of this policy experiment in your sector?

Drugs are often used for reducing the blood pressure of hypertensive patients (those with high blood pressure). An experiment was run to investigate the effect of Drug (A or B) and Dose Level (Low or High) on the reduction in blood pressure. The experiment was conducted separately for the 36 patients who had mild hypertension and the 24 patients who had severe hypertension as the researcher suspected that results may differ for the two groups. For this design, there are:

Design an experiment in which you would perform some sort of hypothesis test about frequencies. For your chosen experiment, explain your entire experimental design. What is your population of interest? How are you going to randomly sample the pop? How many replicates will you collect? What will be the form of the data you collect and what test will you perform? What is your null and alternative hypothesis?

A fair coin is tossed until the first head occurs. Do this experiment T = 10; 100; 1,000; 10,000 times in R, and plot the relative frequencies of this occurring at the ith toss, for suitable values of i. Compare this plot to the pmf that should govern such an experiment. Show that they converge as T increases. What is the expected number of tosses required? For each value of T, what is the sample average of the number of tosses required?

part1. A double-blind design is important in an experiment because there is a natural tendency for subjects in an experiment to want to please the researcher.

a. True

b. False

part 2.

Sampling error concerns natural variation between samples, and is always present.

a. True

b. False

part 3. Sampling error can only be eliminated when conducting a questionnaire of students and every question is a closed question.

a. True

b. False

Suppose you want to test the causal claim about chewing gum improving your mood and focus. How could you design an experiment to test this claim? What would the variables be? Would each be manip- ulated or measured? What results would you expect? Sketch a graph of the outcomes you would predict. Would your experiment satisfy the three criteria for supporting a causal statement?

Why is it important for the researcher to control extraneous environmental and social variables in an experiment? How does a researcher do this?

what is the minimum number of IV conditions in an experiment?

What are experimental and control groups? Do all experiments have to have a control groups?

What are experimental and control groups? Do all experiments have to have a control group.

How can you tell if a variable can serve as an IV?

What is a drying agent? When do you use it? What is the drying agent used in the lab? How much drying agent do you use? It has been suggested that drying agents can be collected after an experiment and the hydrated salt heated in an oven to drive off the water. The recycled drying agent can then be used again for another experiment. Is this a good idea? Give advantages and disadvantages of this proposal.

QUESTION 13

1. Implement in Python and test the classes shown in the UML below. The LibraryItem class shown in the UML, represents an item that the library issues to students. The partial Python code is provided and It has the following attributes. Test the program by creating a list of books and a list of DVDs and printing the details of each element in the list.

   Attribute	Description
   ID	The ID of the item.
   createdate	The date the item was created as dd/mm/yyyy
   title	The title of the item.

   class LibraryItem:
       def __init__(self,ID="",year=0,title=""):
           self.ID=ID
           self.year=year
           self.title=title
   
       def getLoanPeriod(self):
           return 0
   

   A) Implement the Book class. It inherits from LibraryItem. Furthermore, it has this additional attribute

   Attribute	Description
   author	The author of the book
   Electronic	This tells whether the book is available as an electronic book (e book)

   Implement the getLoanPeriod function in this way:

   - If the book was written before the year 2000, the loan period will be 14 days.

   - If the book was written after or in 2000, the loan period will be 7 days.

   B) Implement the DVD class. It inherits from LibraryItem. Furthermore, it has this additional attribute

   Attribute	Description
   length	The length of the DVD. Example: “2 hours: 30 minutes”
   HD	Whether the DVD is available in HD (High Definition) or not

   Implement the getLoanPeriod function in this way:

   - If the DVD is available in HD format, the loan period will be 3 days. Otherwise, the loan period will be 7 days.

Only Question 2 (a, b, c) , but Question 1 is more background information.

An experiment focuses on the differences among apple species. Species A was randomly selected out of 4 species in the experiment

1. What if you want to choose Spcies A. ali or Species A. pub. What is the probability that you choose one or the other?

a. P(A. ali or A. pub) =

b. This can be done by adding probabilities. Write an equation if possible.

c. Will these 2 events be mutually exclusive?

2. For the experiment of the 4 apple species, ¼ of the seeds were bought randomly from a friend and then the rest of the seeds were randomly bought from a neighbor.

a.What is the probability that the one you select is either species A. ali or from a neighbor?

b. will the two events be mutually exclusive?

c. What will the general equation be?