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According to a report, 67.4% of murders are committed with a firearm. (a) If 200 murders are randomly selected, how many would we expect to be committed with a firearm? (b) Would it be unusual to observe 147 murders by firearm in a random sample of 200 murders? Why?
A manufacturer of apple phone charges claims that only 4% of his production is defective. In a random sample of 120 items, the defect rate is 4.99%. At the 1% level of significance, test the manager's claim.
i. State the null and alternative hypotheses for the test. [2]
ii. Calculate the value of the test statistic for this test. [2]
iii. Determine the critical region(s) for this test. [2]
iv. State the conclusion of this test. Give a reason for your answer. [3]
A bottled water company has found in the past that 2% of their bottled water does not meet the company’s high standards. As such periodic samples are taken and tested for their quality. If from the last batch a sample of 12 bottles are taken and tested, determine the probability:
i. Carefully defining the random variable of interest [1]
ii. What is the probability distribution? State the values of the parameters [2]
iii. Justifying the suitability of the probability distribution identified in part (ii) [4]
iv. Calculate the probability that at most 2 bottles do not meet the company’s Standards [4]
v. The expected number of bottles that do not meet the company’s standards. [2]
vi. The amount of sodium sulfate, in mg, found in the bottled water follows a normal distribution with a mean 13mg and a standard deviation of 2.5mg. It is known that 76% of the bottles have a mean that is more than x mg. Find the value of x
The 1500 students weight are normally distributed with a mean of 50kg with the standard deviation of S-5 lbs?
A. How many students are less than 46kg
B. How many students are heavier than 113.5lbs
According to a survey, 32% of drivers tailgate other vehicles before passing them (thinking it will incite them to speed up). Consider 45 drivers selected at random. Use a normal approximation to find the probability that:
(a) at least 17 drivers tailgate? (Use only 3 decimal places)
(b) more than 9 but less than 25 drivers tailgate? (Use only 3 decimal places) ans_a is 0.251
according to study the average number of hours of tv of viewing per household per week is philippines is 50.4 hours and the standard deviation is 11.8 hours.if a random sample of 42 households is taken what is the probability that the sample average is less than 47.5 hours
A golf ball is selected at random from a golf bag. If the golf bag contains 8 type A balls, 5 type B balls, and 3 type C balls, find the probability that the golf ball is not a type A ball.
The score in the final test in statistics and probability of all grade 11 students in a certain school are normally distributed.If the population mean u=50 and the population standard deviation
The average height of Grade 10 students 148 cm. A sample of 250 male students had an average height of 148.3 cm with a standard deviation of 8 cm. Is there a significant difference between the height of the students?
a populatpion of 1,000 students has an average weekly allowance of =350 and standard deviation of =56.13 .what is the probability that a random sample of size =30 will have an average weekly allowance between 335 and 360?
#340153 on Dec 2023