Statistics practical part 2

Task 1
You are a tax inspector and you are instructed to check the data of the complete accounting of commercial tents in your area. In total, there are 1000 food stalls registered with the tax office (group A); 500 stalls selling industrial goods (group B) and 150 - other types of goods (group C). After checking the tents, you found that during the control walk, instead of 250 tents (A), registered with a complete count, there were 270 of them; instead of 100 tents (group B) - 115; instead of 30 tents (group B) - 32. How will you transfer your sample data to the entire population of tents in your area?
Task 2
You are an employee of a public opinion research center. Besides, you are an avid gambler at heart. The presidential elections are just around the corner, and you are looking at the results of a poll conducted by two independent companies assessing who will win the elections. Company "A" used phone books as a population. After randomly selecting 4 million addresses, she sent out postcards across the country asking about attitudes towards presidential candidates. Having spent a large sum on mailing and processing postcards, “A” announced “her” candidate.
Another company "B" made its judgment on the basis of 4 thousand questionnaires, taking into account the opinion of people representing different sectors of society (the division into social groups was appropriately argued). Opinions "A" and "B" were opposite.
Which company (which candidate) will you stake on, and why?
Task 3
You are the head of the credit department of the bank. Faced with non-repayment of loans, you decide: henceforth to issue loans only to companies that are “similar” to those that have proven themselves well, and not to issue to those that are “similar” to defaulters or fraudsters. First you need to collect statistics about both. What indicators of firms' performance, in your opinion, should help you draw the correct conclusion in the future? What statistical methods will you need to use to process the statistical population? How will you use them?
Task 4
You are a private entrepreneur. Your property has a garage for four spaces. In addition, you have at your disposal a tank of gasoline, which your father-in-law (also an entrepreneur, but richer than you) fills for you at the rate of 0.1 cu. for 1 liter. You are faced with the following choice: you need to choose four cars for your garage, but so that the profit from their operation is as large as possible. Any set of four cars costs the same (all used cars). Their consumption of gasoline and the number of kilometers that the cars pass per day and the proceeds from the operation of each car are different. To calculate, you need the data from Table 4.1:
Task 5
You are a broker of a company that sells shares in Russian mining companies. A client contacted you to advise him on the purchase of shares in a zinc mining company.
Estimate the change in production, import and export of zinc using the relative values ​​of the dynamics with a variable base of comparison (chain indices).
Table 5.1
Показатели 1991 1992 1993 1994 1995
Добыча 580 158 154 147 131
Импорт 32 5 129 73 6
Экспорт 33 29 88 301 162
What advice can you give your client?
Task 6
You are an employee of an insurance company. Computers are unstable in your company. The management decided to urgently check them. But there is not much money to be scattered. Therefore, the problem is formulated as follows: the insurance company has 160 computers of 4 types: 1st - 32, 2nd - 48, 3rd - 64 and 4th - 16. A sample survey is organized on the basis of a typical sample. The selection within the types of computers is mechanical, non-repeatable. How many computers should be selected for checking so that with a probability of 0,683, the error in estimating the average number of failed computers does not exceed 5 units (computers)? Based on the materials of the previous survey, it is known that the variance of a typical sample is 739.
Task 7
You are a novice trader (currency dealer). You haven't decided