QBA 775 Quiz 1-3
_____ are collected from several entities at the same point in time.
Cross-sectional data
In a normal distribution, which is greater, the mean or the median?
Neither the mean or the median (they are equal)
Two events are independent if _____.
P(A | B) = P(A) or P(B | A) = P(B)
An initial estimate of the probabilities of events is a _____ probability.
Prior
The amount of time taken by each of 10 students in a class to complete an exam is an example of what type of data?
Quantitative data
Identify the shape of the distribution in the figure below.
Skewed right
Which of the following graphs provides information on outliers and IQR of a data set?
box plot
Which of the following is not a characteristic of the normal probability distribution? a. The mean of the distribution can be negative, zero, or positive. b. The distribution is symmetrical. c. The standard deviation must be 1. d. The mean, median, and the mode are equal.
c. The standard deviation must be 1.
When the expected value of the point estimator is equal to the population parameter it estimates, it is said to be _____.
c. unbiased
Which of the following is a discrete random variable? a. The amount of gasoline purchased by a customer b. The height of water-oak trees c. The amount of mercury found in fish caught in the Gulf of Mexico d. The number of times a student guesses the answers to questions on a certain test
d. The number of times a student guesses the answers to questions on a certain test
The finite correction factor should be used in the computation of the standard deviation of the sample mean and the standard population when n / N is _____.
greater than 0.05
The letter grades (A, B, C, D, F) of business analysis students are recorded by a professor. This variable's classification _____.
is categorical data
Any data value with a z-score less than -3 or greater than +3 is considered to be a(n) _____.
outlier
Bayes' theorem is a method used to compute _____ probabilities.
posterior
The act of collecting data that are representative of the population data is called _____.
random sampling
Sample space is _____.
the collection of all possible outcomes
What is the total area under the normal distribution curve? a. 100 b. 1 c. It must be calculated d. It depends upon the mean and standard deviation
b. 1
The variance is based on the _____.
b. deviation about the mean
The purpose of statistical inference is to make estimates or draw conclusions about a _____.
b. population based upon information obtained from the sample
A parameter is a numerical measure from a population, such as _____.
b. μ
A simple random sample of size n from a finite population of size N is a sample selected such that each possible sample of size _____.
d. n has the same probability of being selected
The population parameter value and the point estimate differ because a sample is not a census of the entire population, but it is being used to develop the _____.
d. point estimate
The basis for using a normal probability distribution to approximate the sampling distribution of the sample means and population mean is _____.
d. the central limit theorem
A variable that can only take on specific numeric values is called a _____.
discrete random variable
