The mass of an empty flask is determined on a balance. It is then filled with N2 and its mass measured. The same flask is then evacuated of N2 and refilled with an unknown gas at the same temperature and pressure and its mass determined.

Mass of empty flask =    88.15g

Mass of flask and unknown gas = 91.30g

Mass of flask and N2 =   89.67ga.

a. What is the relative mass of 1 molecule of the unknown to 1 molecule of N2?

b. What is the molar mass of the unknown gas?

c. If the unknown gas has 2 carbons to 5 hydrogens, what is the empirical formula?

d. What is the molecular formula of the unknown?

1. Explain why, if you measure poverty according to the Supplemental Poverty Measure, the Earned Income Tax Credit (EITC) reduces poverty the most of any program except for Social Security, but if you measure poverty according to the Poverty Gap, the EITC is less effective at reducing poverty. (15 points)

2. In the paper “The EITC and the Extensive Margin: A Reappraisal,” Kleven says that the increases in the EITC in the mid-1990s did not increase the employment rates of mothers as much as had previously been thought. Give at least one of the pieces of empirical evidence Kleven relies on for that claim. (5 points)

(1 point) final scores in a mathematics course are normally distributed with a mean of 71 and a standard deviation of 13. Based on the above information and a Z-table, fill in the blanks in the table below.  

Precision and other notes: (1) Percentiles should be recorded in percentage form to three decimal places.  
(2) Note that this problem does not use the rough values of the 68-95-99.7 rule (that is, the empirical rule); instead you must use more precise Z-table values for percentiles.

This question will ask you about the sequential search theory of unemployment.

a) What is the reservation wage?

b) What does sequential search theory predict about its behavior over the unemployment spell?

c) In the data, reservation wages typically decline over the unemployment spell. Provide 3 possible reasons why this might be the case.

d) Are declining reservation wages consistent or inconsistent with negative duration dependence?

e) How might you reconcile the empirical regularities of (i) declining reservation wages and (ii) negative duration dependence?

The life spans of a species of fruit fly have a​ bell-shaped distribution, with a mean of 34 days and a standard deviation of 4 days. ​(a) The life spans of three randomly selected fruit flies are 36 ​days, 31 ​days, and 46 days. Find the​ z-score that corresponds to each life span. Determine whether any of these life spans are unusual. ​(b) The life spans of three randomly selected fruit flies are 26 ​days, 30 ​days, and 46 days. Using the Empirical​ Rule, find the percentile that corresponds to each life span.

For a 4-unit class like Statistics, students should spend average of 12 hours studying for the class. A survey was done on 24 students, and the distribution of total study hours per week is bell-shaped with a mean of 14 hours and a standard deviation of 3.4 hours.

Use the Empirical Rule to answer the following questions.

a) 68% of the students spend between  hours and  hours on Statistics each week.

b) 95% of the students spend between  hours and  hours on Statistics each week.

c) 99.7% of the students spend between  hours and  hours on Statistics each week.

For a 4-unit class like Statistics, students should spend average of 12 hours studying for the class. A survey was done on 20 students, and the distribution of total study hours per week is bell-shaped with a mean of 13 hours and a standard deviation of 3.4 hours. Use the Empirical Rule to answer the following questions. a) 68% of the students spend between - hours and - hours on Statistics each week. b) 95% of the students spend between - hours and - hours on Statistics each week. c) 99.7% of the students spend between - hours and - hours on Statistics each week.

Please label your work correctly and make them as visible and coherent as possible.

1)In your own words, explain the Simpsons Paradox.

2)How does the coefficient of determination differ from the correlation coefficient?

3)Explain the difference between the empirical method and the classical method of calculating probabilities.

4) In your own words, describe what it means for two events to be mutually exclusive, or disjoint. Give an example of two events that are mutually exclusive/disjoint.

5) Explain the difference between correlation and causation. When is it appropriate to state that the correlation implies causation?

McDonald’s runs two business models. Some McDonald’s restaurants are wholly-owned and operated by the parent company, while some McDonald’s restaurants follow a franchise model i.e. the parent company charges a franchise fee and the restaurant is then independently owned and operated by the franchise owner. Empirical evidence suggests that McDonald's restaurants that are wholly-owned by the parent company (the first type described above) charge lower prices than the prices charged by independent franchises of the company (the second type described above). How can this difference in prices charged be explained?