4. Problems and Applications Q4 Consider the market for mobile applications, smartphones, and conventional phones.
For each pair, identify whether they are complements or substitutes:
Pairs of Goods and Services
Complements
Substitutes
Mobile applications and smartphones

Mobile applications and conventional phones

Smartphones and conventional phones

Suppose a network externality reduces the cost of developing cell phone applications.
Show the effect of this change on the market for cell phone applications.
Demand
Supply
Price of Cell Phone Applications
Quantity of Cell Phone Applications
Demand

S
1

S
2

Next, show the effect the previous change in the market for cell phone applications has on the market for conventional phones.
Demand
Supply
Price of Conventional Phones
Quantity of Conventional Phones
D
1

D
2

Supply

Finally, show the effect the previous change in the market for cell phone applications has on the market for smartphones.
Demand
Supply
Price of Smartphones
Quantity of Smartphones
Demand

Supply

Consider the local telephone company, a natural monopoly. the following graph shows the monthly demand curve for phone services and the company’s marginal revenue (mr), marginal cost (mc), and average total cost (atc) curves. 0 2 4 6 8 10 12 14 16 18 20 100 90 80 70 60 50 40 30 20 10 0 price (dollars per subscription) quantity (thousands of subscriptions) d mr mc atc 8, 60 suppose that the government has decided not to regulate this industry, and the firm is free to maximize profits, without constraints. complete the first row of the following table. pricing mechanism short run long-run decision quantity price profit (subscriptions) (dollars per subscription) profit maximization marginal-cost pricing average-cost pricing suppose that the government forces the monopolist to set the price equal to marginal cost. complete the second row of the previous table. suppose that the government forces the monopolist to set the price equal to average total cost. complete the third row of the previous table. under average-cost pricing, the government will raise the price of output whenever a firm’s costs increase, and lower the price whenever a firm’s costs decrease. over time, under the average-cost pricing policy, what will the local telephone company most likely do

1. descriptive statistics quickly describe large amounts of data can predict future stock returns with surprising accuracy statisticians understand non-numeric information, like colors refer mainly to patterns that can be found in data 2. a 15% return on a stock means that 15% of the original purchase price of the stock returns to the seller at the end of the year 15% of the people who purchased the stock will see a return the stock is worth 15% more at the end of the year than at the beginning the stock has lost 15% of its value since it was originally sold 3. a stock purchased on january 1 cost $4.35 per share. the same stock, sold on december 31 of the same year, brought in $4.75 per share. what was the approximate return on this stock? 0.09% 109% 1.09% 9% 4. a stock sells for $6.99 on december 31, providing the seller with a 6% annual return. what was the price of the stock at the beginning of the year? $6.59 $1.16 $7.42 $5.84

1. revising for conciseness - eliminating flabby expressions,limiting long lead-ins, and dropping unnecessary fillerstime is money in any business environment. people want information communicated quickly and clearly. to make your writing more concise and understandable, avoid flabby expressions, long lead-ins, and unnecessary fillers. your audience will appreciate your brevity.1. if your writing contains a flabby expression like in view of the fact that, replace it with the word because / although / probably .for each of the following two sentences, choose the best revision.2. i am sending you this letter to inform you that we have experienced an unexpected surprise within our expense sheet, but we are positively certain we will solve it.1) we need to inform you that we have experienced an unexpected surprise with our expense sheet, but we are midway to an end result.2) we have identified a problem with our expense sheet, but we will solve it.3) i am sending you this letter to inform you that we have a problem with our expense sheet, but we are positively certain we have a solution.3. it is the user who should contact the center.1) everyone knows that it is the user who should contact the center.2) the user should contact the center.3) if there is a problem, the user should contact the center.read the following passage, and then answer the question.[1] you scheduled seven conference calls for this morning between 10 and 11 a.m. [2] generally, the company limits the number of conference calls to three per hour. [3] i’m letting you know that in the future, we should be more careful about scheduling.4. which revision limits the long lead-in in sentence 3? 1) in the future, we should be more careful about scheduling.2) i’m letting you know so that in the future we are more careful about scheduling calls.3) so that you know in the future, we should be more careful about scheduling.