Class 12 CBSE Applied Maths Inferential Statistics Exercise 10.2
Class 12 CBSE Applied Maths aims to develop an understanding of basic
mathematical and statistical tools and their
applications in the field of commerce (business/ finance/economics) and social
sciences. Topics covered in Class 12th Applied Maths includes : Numbers, Quantification and
Numerical Applications, Algebra, Calculus, Probability Distributions , Inferential Statistics, Index
Numbers and Time-based data , Financial Mathematics , Linear Programming.
Please Select
Q1.
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Q2.
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Q3.
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Q4.
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Q5.
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Q6. A 99% confidence interval for a population mean was reported to be 83 to 87. If σ = 8, what sample size was used in this study?
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Q7.
A simple random sample of 800.elements generates a sample proportion p-(p bar) = 0.70
(i) Provide a 90% confidence interval for the population proportion.
(ii) Provide a 95% confidence interval for the population proportion.
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Q8. In a survey, the sample proportion for the population proportion is p-(p bar) = 0.35. How large a sample should be taken to provide a 95% confidence level with a margin of error of 0.05?
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Q9.
A survey of 611 office workers investigated telephone answering practices, including
how often each office worker was able to answer incoming telephone calls and how often
incoming telephone calls went directly to voice mail. A total of 281 office workers indicates
that they never need voice mail and are able to take every telephone call.
(i) What is the point estimate of the population proportion of office workers who are able
to take every telephone call?
(ii) At 90% confidence level, what is the margin of error?
(iii) What is the 90% confidence interval for the proportion of population of office workers
who are able to take every telephone call?
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Q10.
According to a financial report, the majority of companies reporting profits had beaten
estimates. A sample of 162 companies showed 104 beat estimates, 29 matched estimates and
29 fell short.
(i) What is the point estimate of the proportion that fell short of estimates?
(ii) Determine the margin of error and provide a 95% confidence interval for the proportion
that beates estimates.
(iii) How large a sample is needed if the desired margin of error is 0.05?
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