Business Statistics Assignment 4 Manish Chauhan (09-1128)

SRI BALAJI UNIVERSITY PUNE (SBUP)
BIMM
SEMESTER-I-BATCH -2020-22
BUSINESS STATISTICS
ASSIGNMENT –4 (UNIT-4)
(a) Name of Student: - Manish Chauhan

(b) Reg. No: - 09-1128
(c) Specialization: - Marketing
(d) Batch: - 2020-2022
(e) Institute: - Balaji Institute of Modern Management
(f) Semester: - Semester 1
(g) Subject Name: - Business Statistics
(h) Assignment No: - 4
(i) Submission Date: -27/11/2020
(j) Total no. of pages written: - 19
*QUESTIONS*
Question1.
The life of a certain type of electronic component is normally distributed with

mean=220 hours and standard deviation of 25 hours. Do you agree that the probability
that the mean life of sample of 20 components will be greater than 225 hours will be
higher than probability that the mean life of a sample of 40 components will be greater
than to 225 hours? Show by calculations.
Question2.
An Orange juice producer buys all oranges from a large Orange Groove. The amount of
juice squeezed from each orange is approximately normally distributed with mean of
4.70 ounces and a standard deviation of 0.40 ounces.
(a) What is the probability that randomly selected Orange will contains between 5
and 5.50 ounces?
(b) Between what two values (in ounces) symmetrically distributed around the
population mean will 80% of oranges fall?
(c) Suppose a sample of 25 oranges is selected. What is the probability that the
sample mean will be at least 4.60 ounces?
Question3.
For a random sample of size 30 from a population with mean of 205 and
standard deviation of 25, what is the probability that the sample mean will be:-
(a) Greater than 210?
(b) Less than 200?
(c) Between 190 and 200?
(d) Either less than 210 or more than 220?
Question4.
Give a population each of whose elements falls in one of the two categories, known as
success and failure respectively where probability of success is 0.4. From this population
of size 600 is taken.
(a) What is the expected number of success?
(b) What is the expected value and standard error of the distribution of proportion
of success?
(c) What is the probability that the proportion of success in the sample will be at
most 0.43?
(d) What is the probability that the percentage of failure in the sample will be 55
and 65?
Question5.
Long distance telephone calls are normally distributed with the σ=3 minutes.
(a) Obtain a 90% confidence interval for the population mean, μ if a random
sample of 24 calls was found to have mean =7.8 minutes.
(b) Obtain a 96% confidence interval for the population mean, μ if a random
sample of 240 calls was found to have mean =7.8 minutes.
Question6.
In an automatic self-safety test conducted by a safety Research Centre, the
average tyre pressure in a sample of 102 Tyres was found to be 26 Pounds per
square inch and the standard deviation was 2.62 Pounds per square inch.
(a) What is estimated standard deviation of the population (population consists of 40
million tyres).
(b) Calculate the standard error of the mean.
(c) Calculate a 92% confidence interval for population mean.
Question7.
A manufacturing company produces electric insulation if the insulators break when in
use; a short circuit is likely to occur. To test the strength of the insulator, destructive
testing in high-powered lab is carried out to determine how much force in pound
is required to break the insulators. It is desired to estimate the population mean
force needed to break the insulator to within ±25 pounds of the true value with 90%
level of confidence. On the basis of study taken in the previous year, the standard
deviation is believed to be 120 pounds. What sample size is needed? What sample size is
needed if the level of confidence is to 95%?
Question8.
A bank officer wants to determine the amount of average total monthly deposit
per customer at the bank. He believes on estimate of this average amount using
a confidence interval is sufficient. How large a sample should he take to be
within 300 rupees of actual average with 99% confidence? He assumes standard
deviation of monthly deposit for all the customers is about 1200 rupees?
Question9.
At a Palika car parking lot, 42 cars out of total 150 selected at random were found to be
white
(a) Obtain a point estimate of the proportion of white car in the city and a
98% confidence interval of proportion?
(b) How large a sample would be needed to estimate the proportion of white cars
within ±0.08 of the true proportion at 90% confidence level?
(c) How large a sample would be needed to estimate the proportion of white cars
within ±0.04 of the true proportion of 95% confidence level?
Question10.
Johnson’s machine company has a contract with one of its customer to supply
machine pump gears. One requirement is that diameter of its gear be within specific
limits. Here are the diameters in (inches) of a sample of 20 gears.
4.01 4.00 4.02 4.20 4.03 4.00 3.98 3.99 3.99 4.01
3.99 3.98 3.97 4.00 4.02 4.01 1.02 4.00 4.01 3.99
What can John say to its customer about the diameters of 95% of the gears they are
receiving?
*ANSWERS*

Business Statistics Assignment 4 Manish Chauhan (09-1128)

Uploaded by

Copyright:

Available Formats

Business Statistics Assignment 4 Manish Chauhan (09-1128)

Uploaded by

Document Information

Original Description:

Original Title

Copyright

Available Formats

Share this document

Share or Embed Document

Sharing Options

Did you find this document useful?

Is this content inappropriate?

Copyright:

Available Formats

Business Statistics Assignment 4 Manish Chauhan (09-1128)

Uploaded by

Copyright:

Available Formats

SRI BALAJI UNIVERSITY PUNE (SBUP)

(a) Name of Student: - Manish Chauhan

The life of a certain type of electronic component is normally distributed with

You might also like