IEE 380 EXAM 2 QUESTIONS ANSWERED CORRECTLY LATEST UPDATE 2026
The sample mean is analogous to the center of mass in mechanics. - Answers True
The units associated with the sample standard deviation are the squared measurement units of the
original sample. - Answers False
If the sample variance is calculated from a sample of n observations, then it has n - 1 degrees of
freedom. - Answers True
The median of a sample is the most frequently occurring value in the sample. - Answers False
Discrete random variables take on values across a continuum. - Answers False
The binomial distribution arises from a series of Bernoulli trials. - Answers True
The Poisson distribution is widely used as a model of the number of events in an interval. - Answers
True
The probability mass function of a discrete random variable is a description of the probabilities
associated with each possible value of the random variable. - Answers True
The sum of all of the probabilities in a probability mass function equals unity. - Answers True
The cumulative distribution function, F(x), of a discrete random variable is the sum of all of the
probabilities that are less than or equal to x, where x is a specific value of the discrete random
variable, X. - Answers True
The probability distribution of a statistic is called a sampling distribution. - Answers True
A statistic is a function of observations. - Answers True
All of the observations in a random sample are independent. - Answers True
'The central limit theorem states that the distribution of the mean of independent, identically
distributed random variables with finite variance is the normal distribution. - Answers True
A point estimator of an unknown parameter is unbiased if the expected value of the estimator equals
the parameter. - Answers True
For a fixed value of the standard deviation and a fixed sample size, a confidence interval on the
population mean will get longer as the level of confidence increases from 96% to 99%. - Answers True
For a fixed value of the standard deviation, a 95% confidence interval on the population mean will get
shorter if the sample size increases. - Answers True
This is a correct statement of a statistical hypothesis:
H0: X bar = 10 - Answers False
A type II error occurs if we fail to reject the null hypothesis when it is false. - Answers True
A type I error occurs if the null hypothesis is rejected when it is actually true. - Answers True
The power of a statistical test is 1 - Probability(type II error). - Answers True
The P-value is the smallest level of significance that would lead to rejection of the null hypothesis. -
Answers True
If the variances of two discrete random variables are equal, then the means are equal. - Answers
False
The mean of a discrete random variable is its expected value. - Answers True
The standard deviation of a discrete random variable is the square of its variance. - Answers False
The sample mean is the arithmetic average of all the observations in a sample. - Answers True
The sample mean is analogous to the center of mass in mechanics. - Answers True
If the sample variance is calculated from a sample of n observations, then it has n - 1 degrees of
freedom. - Answers True
The sample mean is analogous to the center of mass in mechanics. - Answers True
The units associated with the sample standard deviation are the squared measurement units of the
original sample. - Answers False
If the sample variance is calculated from a sample of n observations, then it has n - 1 degrees of
freedom. - Answers True
The median of a sample is the most frequently occurring value in the sample. - Answers False
Discrete random variables take on values across a continuum. - Answers False
The binomial distribution arises from a series of Bernoulli trials. - Answers True
The Poisson distribution is widely used as a model of the number of events in an interval. - Answers
True
The probability mass function of a discrete random variable is a description of the probabilities
associated with each possible value of the random variable. - Answers True
The sum of all of the probabilities in a probability mass function equals unity. - Answers True
The cumulative distribution function, F(x), of a discrete random variable is the sum of all of the
probabilities that are less than or equal to x, where x is a specific value of the discrete random
variable, X. - Answers True
The probability distribution of a statistic is called a sampling distribution. - Answers True
A statistic is a function of observations. - Answers True
All of the observations in a random sample are independent. - Answers True
'The central limit theorem states that the distribution of the mean of independent, identically
distributed random variables with finite variance is the normal distribution. - Answers True
A point estimator of an unknown parameter is unbiased if the expected value of the estimator equals
the parameter. - Answers True
For a fixed value of the standard deviation and a fixed sample size, a confidence interval on the
population mean will get longer as the level of confidence increases from 96% to 99%. - Answers True
For a fixed value of the standard deviation, a 95% confidence interval on the population mean will get
shorter if the sample size increases. - Answers True
This is a correct statement of a statistical hypothesis:
H0: X bar = 10 - Answers False
A type II error occurs if we fail to reject the null hypothesis when it is false. - Answers True
A type I error occurs if the null hypothesis is rejected when it is actually true. - Answers True
The power of a statistical test is 1 - Probability(type II error). - Answers True
The P-value is the smallest level of significance that would lead to rejection of the null hypothesis. -
Answers True
If the variances of two discrete random variables are equal, then the means are equal. - Answers
False
The mean of a discrete random variable is its expected value. - Answers True
The standard deviation of a discrete random variable is the square of its variance. - Answers False
The sample mean is the arithmetic average of all the observations in a sample. - Answers True
The sample mean is analogous to the center of mass in mechanics. - Answers True
If the sample variance is calculated from a sample of n observations, then it has n - 1 degrees of
freedom. - Answers True
