2) Suppose that scores on the SAT form a normal distribution with μ = 500 and σ = 100. A high school counselor has developed a special course designed to boost SAT scores. A random sample of n = 16 students is selected to take the course and then the SAT. The sample had an average score of 554. Does the course have an effect on SAT scores?

    a) What are the dependent and independent variables in this experiment?

    b) Perform the hypothesis test using α = .05.

    c) If α = .01 were used instead, what z-score values would be associated with the critical region?

    d) For part c), what decision should be made regarding H₀? Compare to part b), and explain the

         difference.

An organizational psychologist was asked to test a claim by a franchise swimming instruction program. Specifically, the franchisers claimed that they could teach the average 7-year-old to swim across an Olympic-size pool in less than 2 hours. The psychologist arranged for eight randomly selected 7-year-old children to take instruction at this school and kept a record of how long it took each child to swim across the pool. The times (in minutes) were 60, 120, 110, 80, 70, 90, 100, and 130. Following a t test for a single sample (120 minutes is the “known” population mean) using the .01 significance level, what should the psychologist conclude?

Use the five steps of hypothesis testing!

Find a list of at least five related numbers. Compute statistics about the data, and give your interpretation.

Analyze the data you have gathered.

1. Possible sources include the 2010 census, Yahoo finance, and U. S. News and World Report.
2. The data could be sports scores, the national debt, a rate or an amount, such as mortality, literacy, abortion, marriage, high school graduation, college graduation, poverty, income, intelligence quotient, profitability, stock price, dividend, population, or something else.
3. List the data.
4. List your sources.
5. List the statistics you have computed about the data including mean, mode, median, midrange, range, and standard deviation.
6. Give your interpretation of the statistics.

A polling organization collected data on a sample of 60 registered voters regarding a tax on the market value of equity transactions as one remedy for the budget deficit.

a. Compute gamma for the table.
b. Compute tau b or tau c for the same data.
c. What accounts for the differences?
d. Decide which is more suitable for these data.

Please answer all parts. Do not copy answers from other source. NEED FULL EXPLANATION. Please paste excel screenshot if you are using it.

The data in the table below show years of teaching experience and annual salary in dollars for 12 randomly selected mathematics instructors in Illinois colleges/ universities for the 2013-2014 school year. Is there a linear correlation between a mathematics instructor's years of experience and their annual salary?

a. Draw the scatterplot for the variables.

b. Describe the relationship, if any, shown by the scatterplot.

c. Calculate r, the correlation coefficient. How does the correlation coefficient compare to the relationship you saw in the scatterplot?

Number of years: 7 9 6 7 11 12 11 3 3 7 9 1

Salary(in dollars): 48,897 62,866 54,585 56,611 53,541 53,541 47,027 47,970 46,668 48,029 46,735 45,000

1. Suppose the lengths of all fish in an area are normally distributed, with mean μ = 29 cm and standard deviation σ = 4 cm. What is the probability that a fish caught in an area will be between the following lengths? (Round your answers to four decimal places.)
(a) 29 and 37 cm long

(b) 24 and 29 cm long

2.  

The Scholastic Aptitude Test (SAT) scores in mathematics at a certain high school are normally distributed, with a mean of 500 and a standard deviation of 100. What is the probability that an individual chosen at random has the following scores? (Round your answers to four decimal places.)
(a) greater than 600

(b) less than 400

(c) between 550 and 700

Respond to this discussion, what feed back could you give?

Correlation is a statistical technique used to determine the relationship between two or more variables (Thomas, Nelson, & Silverman, 2015). This is a way to determine if there are positive or negative relationships between variables in research. For example, if someone were to research the effect of different amounts of creatine monohydrate supplementation in high school athletes, they may notice a correlation between the amounts of supplementation and the athletes max bench press. Those with a higher supplementation would notice greater gains than those with lower amounts. While their are many other factors to still consider, researchers can use this method to observe relationships and make determinations as to what causes certain outcomes.

For the following three individuals: First, briefly discuss their likelihood to become an entrepreneur; and Second, discuss whether they are likely to be successful (in terms of growth, survival, and creating jobs) if they become an entrepreneur:

1. Tracy is a 30-year-old female married with one child. She studied music at University although never worked in the filed. Her mother inherited a troubled family business when Tracy was very young, but successfully turned it around and made it one of the most successful one in the industry. Tracy was at the family business a lot while growing up, and worked there part-time during the high school years. She and her husband talked about one day to start a business together in the same field.

a) An appliance company advertises that its brand of washing machine will last a lifetime. Well, not really a lifetime, but longer than 10 years. A random sample of 50 machines manufactured in the past 20 years is selected to test this claim at a significance level of .1. If the sample mean is 11 years and the sample standard deviation is 4. Conduct the test of hypothesis.

b) A school states that over 85% of its graduates find employment within the first year after graduating. A recent sample of 400 graduates was selected at random and asked the question, “Did you find employment within the first year after graduating?” and 348 of those responded “Yes”. Test the schools claim at α = .05.

In an attempt to prevent polio, Jonas Salk of the University of Pittsburgh developed a polio vaccine. In a test of its efficacy, a study was carried out in which nearly 2 million grade-school children were enrolled; half were given the vaccine, the other half received a placebo (in this case, an injection of salt water). Neither the children nor the doctors performing the diagnoses knew which children belong to which group. The incidence of polio was far lower in the group that received the Salk vaccine.

(a) (3 points) Is this statistical study an observational study or is it a randomized experiment? Explain
your answer.
(b) (2 points) Is it appropriate to conclude that the vaccine lowers the risk a child will develop polio? Why
or why not?