1. You have been provided information on summary statistical data for two neighborhoods. Specifically, you have been provided calculations on the Average Price Per Square Foot, Average Age and Average, and the Average Prices for houses in the two neighborhoods and the Standard Deviation of each variable. Apply the method of Confidence Intervals at (97%) to Estimate answer the question whether:
   1. Average Age of House in each neighborhood is significantly different from 60 years
   2. Average Price of Houses in each neighborhood is significantly different from $415,000
   3. List at least two reasons that you think that the Average Price of houses and the Average Age of Houses in one neighborhood will be different from the other neighborhood in the file (You may use personal knowledge of the neighborhoods).

      Comparative Descriptive Statistics – Arocher vs Borough Park Average Price per Square Foot, Average Age of House & Average Price of House
      Neighborhood and Sample Size (n)	Average	Standard Error	Standard Deviation
      Average Age of House
      Staten Island, Arocher (40)	39.4250	4.48128	28.34213
      Brooklyn, Borough Park (49)	91.6939	2.04233	14.29628
      Average Price of House
      Staten Island, Arocher (40)	$396,374.30	$14,930.990	$94,431.873
      Brooklyn, Borough Park (49)	$696,638.78	$24,093.715	$168,656.005

Database Management System

Complete the following exercises in Connolly & Begg:

4.8 The following tables from part of a database held in a relational DBMS

Hotel (hotelNo, hotelName, city)

Room (roomNo, hotelNo, type, price)

Booking (hotelNo, guestNo, dateFrom, dateTo, roomNo)

Guest (guestNo, guestName, guestAddress)

a) Identify the foreign keys in this schema.

b) Explain how the entity integrity rule and the referential integrity rule apply to these relations.

5.8 Describe the relations that would be produced by the following relational algebra operations. In your description, make clear what attribute your relations have, and explain what each relation represents in the real world.

a) π_hotelNo(σ_{price > 50}(Room))

b) σ_{Hotel.hotelno = Room.hotelNo}(Hotel × Room)

c) π_hotelName(Hotel ⨝ _{Hotel.hotelNo = Room.hotelNo}(σ_{price > 50}(Room)))

The following tables form part of a Library database held in an RDBMS:

Book (ISBN, title, edition, year)

BookCopy (copyNo, ISBN, available)

Borrower (borrowerNo, borrowerName, borrowerAddress)

BookLoan (copyNo, dateOut, dateDue, borrowerNo)

Formulate the following queries in relational algebra:

5.24 List all book titles

5.25 List all book titles published in the year 2012.

5.27 List all copies of book titles that are available for borrowing.

5.30 List the names of borrowers with overdue book.s

1. Parkruns are free 5km timed runs usually run on weekends in different cities, towns and suburbs around the world. It is suspected that they are competitive and hence faster than 5km family fun runs which require payment for registration. Parkrun finishers do not get medals whereas all family fun run finishers get medals. The summary statistics below are from two random samples of 10 park runners and 10 5km family fun runners in Bellville. The races were run on the same route and on 2 separate days but with identical weather conditions. The summary statistics are for the recorded finishing times (in minutes) of the runners. park runners family fun runners Sample Mean: 20.58 25.67 Sample standard deviation : 3.5 5.7 (a) Is there evidence that the mean finishing time differs between the park runners and family fun runners? Perform an appropriate statistical test. (b) Construct a 95% confidence interval for the difference between the population means of the two groups. Compare your results to your conclusions in (a). (c) What assumption(s) are necessary for performing the hypothesis tests and constructing the confidence interval above? Hint: Use a 5% significance level for the F-test but report a p-value for the t-test

Lavage Rapide is a Canadian company that owns and operates a large automatic carwash facility near Montreal. The following table provides data concerning the company’s costs:

For example, electricity costs are $1,100 per month plus $0.07 per car washed. The company expected to wash 8,100 cars in August and to collect an average of $6.70 per car washed.

The actual operating results for August appear below.

Required:

Compute the company's revenue and spending variances for August. (Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance). Input all amounts as positive values.)

Lavage Rapide is a Canadian company that owns and operates a large automatic car wash facility near Montreal. The following table provides data concerning the company’s costs: Fixed Cost per Month Cost per Car Washed Cleaning supplies $ 0.70 Electricity $ 1,400 $ 0.08 Maintenance $ 0.15 Wages and salaries $ 4,300 $ 0.40 Depreciation $ 8,300 Rent $ 2,200 Administrative expenses $ 1,700 $ 0.04 For example, electricity costs are $1,400 per month plus $0.08 per car washed. The company expects to wash 8,400 cars in August and to collect an average of $6.80 per car washed. The actual operating results for August appear below. Lavage Rapide Income Statement For the Month Ended August 31 Actual cars washed 8,500 Revenue $ 59,220 Expenses: Cleaning supplies 6,380 Electricity 2,042 Maintenance 1,500 Wages and salaries 8,020 Depreciation 8,300 Rent 2,400 Administrative expenses 1,936 Total expense 30,578 Net operating income $ 28,642 Required: Calculate the company's revenue and spending variances for August. (Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance). Input all amounts as positive values.)

Lavage Rapide is a Canadian company that owns and operates a large automatic car wash facility near Montreal. The following table provides data concerning the company’s costs:

For example, electricity costs are $1,400 per month plus $0.08 per car washed. The company expects to wash 8,000 cars in August and to collect an average of $6.90 per car washed.

The actual operating results for August are as follows:

Required:

Calculate the company's revenue and spending variances for August. (Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance). Input all amounts as positive values.)

Lavage Rapide is a Canadian company that owns and operates a large automatic car wash facility near Montreal. The following table provides data concerning the company’s costs:

For example, electricity costs are $1,100 per month plus $0.08 per car washed. The company expects to wash 8,500 cars in August and to collect an average of $6.80 per car washed.

The actual operating results for August are as follows:

Required:

Calculate the company's revenue and spending variances for August. (Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance). Input all amounts as positive values.)

Lavage Rapide is a Canadian company that owns and operates a large automatic car wash facility near Montreal. The following table provides data concerning the company’s costs:

For example, electricity costs are $1,400 per month plus $0.06 per car washed. The company expects to wash 8,200 cars in August and to collect an average of $6.10 per car washed.

The actual operating results for August are as follows:

Required:

Calculate the company's revenue and spending variances for August. (Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance). Input all amounts as positive values.)

Lavage Rapide is a Canadian company that owns and operates a large automatic car wash facility near Montreal. The following table provides data concerning the company’s costs:

For example, electricity costs are $1,300 per month plus $0.09 per car washed. The company expects to wash 8,200 cars in August and to collect an average of $6.40 per car washed.

Required:

Calculate the company's revenue and spending variances for August. (Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance). Input all amounts as positive values.)

Lavage Rapide is a Canadian company that owns and operates a large automatic car wash facility near Montreal. The following table provides data concerning the company’s costs:

For example, electricity costs are $1,400 per month plus $0.09 per car washed. The company expects to wash 8,500 cars in August and to collect an average of $6.00 per car washed.

The actual operating results for August appear below.

Required:

Calculate the company's revenue and spending variances for August. (Indicate the effect of each variance by selecting "F" for favorable, "U" for unfavorable, and "None" for no effect (i.e., zero variance). Input all amounts as positive values.)