Essay About Sample Size And Standard Error

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Out of a population of 100 people, the standard error comes to 2.2kg when calculating their average weight using sampling with replacement and 1.9kg when using sampling without replacement. What is the sample size and standard deviation of the population?Ans: n = 26 approx, [pic 1] The standard deviation of annual household income in a locality is known to be Rs. 1.2 lakh. How many households must be surveyed, so that the sample average is within Rs. 25,000 of the population average 99% of the time? Ans: n=154For a production line to be usable, its goods must be of proper quality at least 99% of the time. If the quality is less, the line is rejected. If a sample run of 300 gives of 280 items of proper quality, can the line be accepted with 95% confidence? A company spends $5M on developing a new product. There is a 20% chance the product will not be successfully developed.  Once developed, the product will be tested at the cost of $2M, with a 60% chance it will pass testing. Once it passes testing, the amount it sells will depend on the competition.With competition10000 units, at selling price $2000/unitWithout competition12000 units at selling price $3000/unitWhat is the expected payoff assuming a pessimistic outlook? Ans: $3M The number of sales a car dealer makes in a day follows the following distribution:SalesProbability30.1240.2850.3360.2070.07Simulate the number of sales in a day for 30 days of operation using Monte Carlo simulation, and find the mean and median number of sales. If the average value of a sale is 2.7lakhs, what is the probability of a day’s total sales exceeding 15 lakhs? Ans: p(x>=15)=0.27