Confidence Intervals and Standard Deviation
In a manufacturing process, the diameter of the steel rods is the product characteristic. A random sample of 25 steel rods is taken and sample mean is 8.88 cm. The diameter is assumed to be normally distributed with standard deviation 1.25. (i) Find a 95% confidence interval for the true diameter. If the standard deviation ...continues
Proportion testing of crime rate using Minitab
Figures for the yearly crime rate (the number of crimes per 1,000 population) in Mississippi, USA from 1993 to 2002 are as follows: 1.35 1.63 2.33 2.41 2.63 2.93 3.41 3.26 3.64 4.51 (i) Display a normal probability plot using Minitab and test whether the data follow a normal distribution. Write down the null and alterna ...continues
Hypothesis Testting, Confidence Intervals and Levels of Significance
In a statistics lecture, students are asked whether or not they enjoyed doing statistics. Random sample of 50 students was taken and 30 of them said that they enjoyed doing statistics. The lecturer claimed that more than 50% of the students enjoyed doing statistics. (i) Test, at the 5% level of significance, whether or not ...continues
Goodness-of-fit Test : Hypothesis Testing
Goodness of fit test : A student was given a die but he had no idea whether or not it was a fair die. He threw the die 480 times and each outcome was recorded. The results are given in the following table. xi 1 2 3 4 5 6 Oi 80 105 95 64 79 57 Test, at the 5% level of significance, whether or not this die is fair. You must s ...continues
Normal approximations to binomial probabilities
Mathematics Study Centre was established to help students to solve mathematics and statistics problems. Assume that 30% of the students seek help in statistics. If 200 students seek help at the MSC in a semester, approximate the probability that at least 55 of them seek help in statistics.
Quantitative Analysis - Waiting lines and queuing Theory models
I have some Quantitative Analysis questions I need help understanding. Waiting lines and queuing Theory models 1. The New Providence shopping mall is considering setting up an information desk manned by one employee. Because of the complex design of the mall, it is expected that people will arrive at the desk at about twi ...continues
I have some Quantitative Analysis questions I need help understanding. Simulation Modeling 1. A certain grocery store has noted the following figures with regard to the number of people who arrive at their three checkout stands ready to check out and the time it takes to check out the individuals. Arrivals/Min. ...continues
Quantitative Analysis - 50 Multiple choice Questions
1. Which of the following is not a reason for the failure of a particular Quantitative analysis technique in solving a problem? a. underestimating the total cost of using quantitative techniques b. failure to define the real problem c. under-emphasis on theory and over-emphasis on application d. underestimating the total ...continues
Draw an influence chart for the following: The Boeing company faces a critical strategic choice in its competition with Airbus Industries for the long-haul flight segment: should it design and build a super-747 model that can carry 550 passengers at speeds around 350 mph, or a plane that can fly at 95 percent of the speed o ...continues
A toy company has been marketing souvenir toys in conjunction with various professional sports teams in a number of cities. Over the past few years, this experience has provided some data on the effect of advertising on sales revenues because the advertising expenditures have tended to be different in each case. Although the l ...continues
