Which of the following conditions must be met to conduct a test for the difference in two sample means?
A. Data must be at least of interval scale.
B. Populations must be normal.
C. Variances in the two populations must be equal.
D. Data must be at least of interval scale and populations must be normal.
Quantitative Analysis
- The measurements of weight of 100 units of a product manufactured by two parallel processes have same mean but the standard of process A is 15 while that of B is 7. What can you conclude?
- Twenty randomly selected statistics students were given 15 multiple-choice questions and 15 open-ended questions, all on the same Material. The professor was interested in determining on which type of questions the students scored higher. This experiment is an example of
- What is the variable used to predict the value of another called?
- What is the chart called when the paired data (the dependent and independent variables) are plotted?
- For a hypothesis test comparing two population means, the combined degrees of freedom are 24. Which of the following statements about the two sample sizes in NOT true? Assume the population standard deviations are equal.
- Suppose we test the difference between two proportions at the 0.05 level of significance. If the computed z is -1.07, what is our decision?
- What is the level of significance?
- A null hypothesis makes a claim about a
- For a standard normal distribution, what is the probability that z is greater than 1.75?
- For the normal distribution, the mean plus and minus 1.96 standard deviations will include about what percent of the observations?
- The mean of any uniform probability distribution is
- The shape of any uniform probability distribution is
- A listing of all possible outcomes of an experiment and their corresponding probability of occurrence is called a
- If two events A and B are mutually exclusive, what does the special rule of addition state?
- The National Center for Health Statistics reported that of every 883 deaths in recent years, 24 resulted from an automobile accident, 182 from cancer, and 333 from heart disease. Using the relative frequency approach, what is the probability that a particular death is due to an automobile accident?
- The test scores for a class of 147 students are computed. What is the location of the test score associated with the third quartile?
- A dot plot shows
- A sample of single persons receiving social security payments revealed these monthly benefits: $826, $699, $1,087, $880, $839, and $965. How many observations are below the median?
- For any data set, which measures of central location have only one value?
- The sum of the deviations of each data value from this measure of central location will always be 0.
- A small sample of computer operators shows monthly incomes of $1,950, $1,775, $2,060, $1,840, $1,795, $1,890, $1,925, and $1,810. What are these ungrouped numbers called?
- Monthly commissions of first-year insurance brokers are $1,270, $1,310, $1,680, $1,380, $1,410, $1,570, $1,180, and $1,420. These figures are referred to as
- Shoe sizes, such as 7B, 10D, and 12EEE, are examples of what level of measurement?
- The names of the positions in a corporation, such as chief operating officer or controller, are examples of what level of measurement?