2.3) Suppose that a piece of equipment produces steel pipes and malfunctions 5% of the time, if the next 4
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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)
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16.Statistics help. Find the mean and standard deviation for the 65 low prices in your sample and provide the printout
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de the printout below. Use these values as estimates of the mean and standard deviation found in the population of all low prices. Suppose that the low prices were normally distributed (regardless of what your data may indicate). Find the proportion of all low prices that would be between $20 and $50 in the population. I want you to show your work. To receive full credit, you should include pictures of the normal curve (labeled with both x and z-values) with the pertinent probabilities shaded in the picture
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19.1. The amount of chilli sauce dispensed from a machine at a local food joint is normally distributed with a
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with a mean of 25 gm and a standard deviation of 5 gm.
(a) If the machine is used 500 times, approximately how many times will it be expected to dispense 30 gm or more of chilli sauce?
(b) How can you decrease this number to half? Give a numerical answer.
2. StarTech manufactures re sensors. They use a protective screen for their sensors to protect it from dust. The sensor becomes useless if the thickness of the screen exceeds 0.5 mm. They outsource the production of the screen to a di erent company that claims to manufacture screens with a mean thickness of 0.3 mm and a standard deviation of 0.1 mm.
(a) If 10000 screens are manufactured how many will be discarded because they are too thick?
(b) If screens less than 0.2 mm are too thin to be used, what is the probability that screens manufactured by the above company will be discarded because they are too thick or too thin? Show the result on a graph.
3. The amount of time that Sam spends playing the guitar is normally distributed with a mean of 15 hours and a standard deviation of 3 hours.
(a) Find the probability that he spends between 15 and 18 hours playing the guitar during a given week.
(b) What is the probability that he spends less than 3 hours playing the guitar during a given week?
4. Soon after he took oce in 1963, President Johnson was approved by 160 out of a sample of 200 Americans. With growing disillusionment over his Vietnam policy, by 1968 he was approved by only 70 out of a sample of 200 Americans.
(a) What is the 90% con dence interval for the percentage of all Americans who approved of Johnson in 1963? In 1968?
(b) What is the 90% con dence interval for the change?
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