1 a. After studying about permutations, solve the following problem. If there are 20 companies that provide dividends in 2022 and are arranged based on company performance where each group consists of 5 companies. How many ways are there to arrange the companies? b. After studying about combinations, solve the following problem. There are 5 banks that apply for portfolio credit to Bank Indonesia. Meanwhile, Bank Indonesia will only choose 2 banks. How many combinations of banks can BI choose? Question 2 A total of 20 companies are included in the August 2022 stock price selection. The stock prices of the 20 companies range from IDR 160-870 per share. What is the probability that the stock price is between 490 and 600 per share. If it is known that X = 490 is the arithmetic mean and the standard deviation is 144.7. Question 3 a. The average travel time from Jakarta to Bandung by train is 120 minutes with a standard deviation of 16 minutes. If the government claims that high-speed trains can shorten travel time to 36 minutes. The travel test was conducted on a high-speed train carrying 64 passengers. Can the implementation of high-speed trains shorten travel time? Use = 0.05 to solve this case. b. Determine the t-table value of the following n and ; - n = 11 and = 0.01 for the left-hand test - n = 25 and = 0.1 for the right-hand test - n = 15 and = 0.05 for a two-tailed test