Search & Filtering
If the events have the same theoretical probability of happening, then they are called
Consider a population consisting of the values (1, 3, 8), n= 2 with replacement.
- Identify the probability of each sample
The time taken to assemble a car in a certain plant is a random variable having a normal
distribution of 20 hours and a standard deviation of 2 hours. What is the probability that a
car can be assembled at this plant in a period of time less than 19.5 hours?
x>0, n>=1, prove that 1 + x + x2 + .....+ x2n >= (2n+1)xn
1. If a population has a mean of 5.7, what is the mean of the sampling distribution of its means?
1. In a survey of 1500 households, it is found that 47% of them have a high-definition television (based on data from the consumer electronics association). Use a 0.01 significance level to test the claim that fewer than half of all households have a high definition television. Are the results from a few years ago likely to be valid today?
A cement manufacturer claims that the average weight of his product is 40 kg: with a standard deviation of 2.35 kg A sample of 45 bags was taken and found to have a mean weight of 38.71 kg: Are we going to accept the claim of the cement manufacturer? Use 0.01 level of significance
1. In a Harris poll of 630 human resource professionals, 38.4 % said that they had at least one child by the age of 30 years.
a. Among the 630 professionals who were surveyed, how many of them said they had at least one child before 30 years of age.
b. Construct a 99% confidence interval estimate for the proportion of all human resource professionals with at least one child before 30 years of age.
c. Repeat part (b) using a confidence interval level of 90%.
d. Compare the confidence intervals from part (b) and (c) and identify the interval that is wider. Why is it wider?
1. A particular brand of petrol was used in 80 randomly chosen cars of the same model and age. The petrol consumption, x miles per gallon, was obtained for each car. The results are summarized by
∑x=1896 and ∑x2=45959.
Calculate a 99% confidence interval for the mean petrol consumption of all cars of this model and age.
Three cars arrive simultaneously at a four way stop and all want to proceed straight through the intersection. How many ways are there for this to happen if they proceed on at a time. Show a diagram with your explanation.
