In the Brunei, letters can be posted by two services, called ‘first class’ and ‘second class’. First class post is intended to be faster. A letter posted first class on a Monday has the following probabilities of arriving on Tuesday to Friday of the same week.   A Wednesday Thursday Friday 0.6 0.2 0.1 0.1 You should assume that the arrival days of letters are independent of one another.  I post three letters first class on Monday. Find the probability that  They all arrive on Tuesday,  None of them arrive on Tuesday,  One arrives on Wednesday, one on Thursday and one on Friday.

Professor Brown gives her students a maximum of three attempts to pass a final examination in her statistics course. She has found that the probability of passing on the first attempt is 0.40, the probability of passing the second attempt is 0.65 and the probability of not passing the third attempt is 0.15. Find the probability that a randomly selected student of hers will pass the final examination

An engineer decides to buy four new snow tires for his car. He finds that Retailer A is offering a special cash rebate, which depends on how much snow falls during the first winter. If this snowfall is less than 50% of the mean annual snowfall for his city, his rebate will bet 50% of the list price. If the snowfall that winter is more than 50% but less than 75% of the mean annual snowfall, his rebate will be 25% of the list price. If the snowfall is more than 75% of the mean annual snowfall, he will receive no rebate. The engineer finds from a reference book that the annual snowfall for his city has a mean of 80 cm and standard deviation of 20 cm and approximates a normal distribution. The list price for the brand and size of tires he wants is $80.00 per tire. The engineer checks other retailers and finds that Retailer B sells the same brand and size of tires with the same warranty for the same list price but offers a discount of 5% of the list price regardless of snowfall that…

Suppose an oil company is thinking of buying some land for $10,000,000. There is a 60%60% chance of economic growth and a 40%40% chance of recession. The probability of discovering oil is 44%44% when there is economic growth and 32%32% when there is a recession. If there is economic growth and the oil company discovers oil, the value of the land will triple. If they do not discover oil, the value of the land will decrease by 10%.10%. If there is a recession and the company discovers oil, the value of the land will increase by 50%.50%. If they do not discover oil, the land will decrease in value by 75%.75%. What is the expected value of the investment? Give your answer to the nearest dollar. Avoid rounding within calculations. $$     Select the correct interpretation of the expected value. The expected value represents what the actual investment value will be for this land purchase of $10,000,000. The company should make the investment because the expected value…