1.(1) The claim by a weight loss Company is that on average, the client will lose 10 pounds over
first 2 weeks. 50 people who joined the programme are sampled, their weight loss is 9 pounds with a standard deviation of 2.8 pounds. Can we conclude at the .05 level that a person joining the programme will lose less than 10 pounds?
(2) The following is a random sample of 90-day futures prices in dollars for 1 troy oz. of silver from The Wall Street Journal issues in May and June of 1997: 4.74, 4.77, 4.87, 4.91, 4.83, 4.72, 4.92, 4.86, 4.97, 4.71, 4.90, 4.93, 4.75, 4.88, 4.79, 4.83, 4.89.
a. Calculate the mean
c. Standard deviation of the 90-day future price of silver data
(3) A mining company needs to estimate the average amount of copper ore per ton mined. A random sample of 50 tons gives a sample mean of 146,75 pounds. The population standard deviation is assumed to be 35.2 pounds.
a. Give a 95% confidence interval for the average amount of copper in the population of tons mined.
b. Give a 90% confidence interval for the average amount of coper per ton
c. Give a 99% confidence interval for the average amount of coper per ton
(4) An e-commerce Website gets 2,385 visitors on a particular day. Among these, 1790 visitors explore the products by looking at more pages at the site. Among these 1790 visitors who explore the products, 387 make a purchase.
a. If a visitor chosen at random from all those who visited the site, what is the probability that the visitor explored the products
b. If a visitor is chosen at random from all those who visited the site, what is the probability that the visitor made a purchase.
c. If a visitor is chosen at random from all those who explored the products, what is the probability that the visitor made a purchase.
d. Which of the preceding three probabilities is relevant to the design of the home page that leads to product page.
3.3) Suppose that a piece of equipment produces steel pipes and malfunctions 5% of the time, if the next 4
xt 4 tests are performed, find P(x=0), P(x=1), P(x=2),P(x=3) and P(x=4). SHOW ALL WORK TO GET CREDIT)
4) Use the confidence interval (99%) to solve the following question. A company is trying to establish the number of average amount of funds that are owed by its employees. They collect 1,000 accounts and found the sample average owed is $250 with a standard deviation of 10. Calculate the confidence interval (MUST SHOW ALL WORK TO GET CREDIT)
5) Use the t distribution formula and table to solve the following question. A random sample of 91 with a sample average of 90 and a standard deviation of 4.2 hours, calculate the confidence interval at 98% (MUST SHOW ALL WORK TO GET CREDIT)
6) A poll of 3,000 adults out of 5,500 was collected to found that they did not get a master’s degree. Calculate the confidence interval at 95%. (MUST SHOW ALL WORK TO GET CREDIT)
8.1. Paul wonders what it would be like to own a house of his own within five years. He now rents
o-bedroom apartment with a friend. He pays half the $740 monthly rent. A two-bedroom bungalow on his street is for sale with an asking price of $107 900 and has annual property taxes of approximately $2800.
a) a. As a first time homebuyer, Paul would need a 5% downpayment. Calculate this amount.
b) How much would Paul need to save each month to have the down payment saved is 5 years? Is this amount and the time period reasonable? Explain.
c. Use a TVM Solver to determine the monthly mortgage payment for this house, less the down payment. Assume the interest rate is 6% per year and the mortgage is amortized over 25 years.
d) Calculate the monthly payment to the bank for the mortgage plus the monthly portion of the property taxes.
e) e. Bills from the current owners show that electricity averages $180 every two months, natural gas averages $115 per month, and water averages $260 every four months. Calculate the average monthly utility expenses for the house.