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WorksheetsTest 3 Semester 3 Matematik T
Total questions: 22
Worksheet time: 54mins
Find the median
50
60
55
45
Find interquartile range
(a)
An IT institute buys computers from three different companies A, B and C. The institute buys 45% of the total number of computers from company A, 30% from company B and 25% from company C.
The percentage of defective computers supplied by company A, company B and company C are 2%, 3% and 4% respectively.
If a company is selected at random, what is the probability that the computer is defective? Give your answer in 3 decimal places.
(a)
An IT institute buys computers from three different companies A, B and C. The institute buys 45% of the total number of computers from company A, 30% from company B and 25% from company C.
The percentage of defective computers supplied by company A, company B and company C are 2%, 3% and 4% respectively.
If a lecturer finds that a computer is defective, what is the probability that the computer is supplied
by company A? Give your answer in 4 decimal places.
(a)
An IT institute buys computers from three different companies A, B and C. The institute buys 45% of the total number of computers from company A, 30% from company B and 25% from company C.
The percentage of defective computers supplied by company A, company B and company C are 2%, 3% and 4% respectively.
If a lecturer finds that a computer is defective, what is the probability that the computer is supplied
by company B? Give your answer in 4 decimal places.
(a)
An IT institute buys computers from three different companies A, B and C. The institute buys 45% of the total number of computers from company A, 30% from company B and 25% from company C.
The percentage of defective computers supplied by company A, company B and company C are 2%, 3% and 4% respectively.
If a lecturer finds that a computer is defective, what is the probability that the computer is supplied
by company C? Give your answer in 4 decimal places.
(a)
Find a
(a)
Given that a = 1/4, Find mean.
(a)
In a stem and leaf plot, what do you need to include
stem
leaf
key
comma
unit
To find cumulative distrubution function for X, you need to...
differentiate f(x)
integrate f(x)
write F(x)
write 0, x<0
write 1, x>1
A company’s management is concerned about the quality of the pens that it provides to their staffs.
The company purchasing department tests a random sample of 200 such pens and finds that 24 of them fail to write immediately. Calculate an approximate 96% confidence interval for the proportion of pens that fail to write immediately. Give your answer in 3 significant figures.
(a)
Given that 96% confidence interval fr the proportion of pens that fail to write is (0.0728, 0.167). The suppliers claim that at most 3 in 50 pens fail to write. Comment on the suppliers claim
since 0.06 does not lie in the interval, reject claim
since 0.06 does not lie in the interval, do not reject claim
since 0.07 does not lie in the interval, reject claim
since 0.07 does not lie in the interval, do not reject claim
what is the test statistic value. Give your answer in 4 decimal places.
(a)
what is the test statistic value. Give your answer in 4 decimal places.
(a)
The weight, X kilograms, of salt in a bag can be modelled by a normal random variable with unknown mean µ and known standard deviation 0.4.
The salt in each of a random sample of 25 bags from a large batch is weighed. The total weight of salt in these 25 bags is found to be 497.5 kg. Construct a 99% confidence interval for the mean weight of salt in bags in the batch. Give your answers in 2 decimal places.
(a)
Given that 99% confidence interval is (19.69, 20.11) for the mean weight of salt in bags. Comment on the claim that bags contain an average of 20kg of salt
20kg lies in CI, do not reject claim
20kg lies in CI, reject claim
The weight, X kilograms, of salt in a bag can be modelled by a normal random variable with unknown mean µ and known standard deviation 0.4. The use of central limit theorem is not required in constructing 99% confidence interval because the weight of salt in a bag is a ______ _________ _________.
(a)
The weight, Y kilograms, of sugar in a bag can be modelled by a normal random variable with mean 25.25 and standard deviation 0.35.
A firm purchases 10 such bags. These bags may be considered to be a random sample.Determine the probability that the mean weight of sugar in the 10 bags is less than 25 kg. Give your answer in 4 decimal places.
(a)
The weight, Y kilograms, of sugar in a bag can be modelled by a normal random variable with mean 25.25 and standard deviation 0.35.
A firm purchases 10 such bags. These bags may be considered to be a random sample. Calculate the probability that the weight of sugar in each of the 10 bags is more than 25kg. Give your answer in 5 decimal places.
(a)
It is claimed that the proportion of people who prefer cooked fresh garden peas to cooked frozen garden peas is greater than 0.5. In an attempt to investigate this claim, a sample of 15 people were each given an unlabeled portion of cooked fresh garden peas and an unlabeled portion of cooked frozen garden peas to taste. After tasting each portion, the people were each asked to state which of the two portions they preferred.
Of the 15 people sampled, 9 preferred the cooked fresh garden peas.
Assuming that the 15 people may be considered to constitute a random sample, perform a hypothesis test, at the 10% significance level, to investigate the claim. What is the alternative hypothesis for this test?
(a)
It is claimed that the proportion of people who prefer cooked fresh garden peas to cooked frozen garden peas is greater than 0.5. In an attempt to investigate this claim, a sample of 15 people were each given an unlabeled portion of cooked fresh garden peas and an unlabeled portion of cooked frozen garden peas to taste. After tasting each portion, the people were each asked to state which of the two portions they preferred.
Of the 15 people sampled, 9 preferred the cooked fresh garden peas.
Assuming that the 15 people may be considered to constitute a random sample, perform a hypothesis test, at the 10% significance level, to investigate the claim. What is the test statistics. Give your answer in 4 decimal places.
(a)
It is claimed that the proportion of people who prefer cooked fresh garden peas to cooked frozen garden peas is greater than 0.5. Perform a hypothesis test, at the 10% significance level, to investigate the claim. Given that of the 500 people sampled, 271 preferred the cooked fresh garden peas.What is the test statistics? Give your answer in 3 decimal places
(a)
