A business enterprise wants to pick out which of the 2 production strategies has the smaller
finishing touch time. One sample of employees is chosen and each worker first makes use of
one technique and then uses the opposite approach. The sampling method getting used to
gather of entirety time facts is based totally on - ANS-Matched samples.
A medical doctor would love to understand if women and men were given the equal amount
of sleep according to night time or if ladies tended to get less sleep than guys. He took a
random sample of 100 of his male and 100 of his female patients and asked them what
number of hours of sleep they were given, according to night time, on average. The ladies
slept a median of 6.75 hours and the guys slept an average of seven.5 hours. Suppose we
additionally knew the populace preferred deviations to be 1.25 hours and 1.Five hours for
women and men, respectively. Formulate the null and alternative hypotheses to test whether
or not women sleep less than men do, on common - ANS-H0:: Um-Um=0, Ha: Um-UW<zero
A speedy food restaurant has automated drink dispensers to assist fill orders more fast.
When the 12 ounce button is pressed, they would like for exactly 12 oz of beverage to be
allotted. There is, however, undoubtedly a few variant in this quantity. The company does not
need the gadget to systematically over fill or under fill the cups. Which of the following gives
the correct set of hypotheses? - ANS-H0: u=12, Ha: u no longer=12
A forecast model of the shape is referred to as a(n) - ANS-Quadratic fashion equation.
A graph of the standardized residuals plotted in opposition to values of the regular rankings
that enables to decide whether or not the belief that the mistake term has a normal
opportunity distribution appears to be legitimate is known as a - ANS-Normal probability plot
A neighborhood entrepreneur would love to recognize if folks that live in a rural network are
much more likely to buy a actual Christmas tree than folks that live in an city network. He
takes a random pattern of 100 folks who live within the town and a separate random pattern
of 100 people who stay within the united states of america and asks them if they buy a
actual tree at Christmas time. Of the urban contributors, 22 buy a actual tree. Of the
agricultural members, 28 purchase a actual tree. Let P1= the percentage of each person
who stay in rural groups and buy a real Christmas tree, and allow P2 = the percentage of all
of us who live in city groups and buy a actual Christmas tree. State the null and alternative
hypotheses. - ANS-H0: p1-p2<0, Ha:p1-p2>zero
A model inside the form of , where each unbiased variable zj (for j = 1, 2,..., p) is a
characteristic of x1, x2,..., xk, is known as the: - ANS-wellknown linear version.
A news reporter states that the common quantity of temperature in January has never
dropped under 10 stages Fahrenheit. You go browsing to research this declare. The suitable
hypotheses are - ANS-H0: u>10, Ha: u<10.
A positive forecast error indicates that the forecasting method _____ the dependent variable.
- ANS-Underestimated.
A researcher recruits 25 people to participate in a study on alcohol consumption and its
interactions with Tylenol. The 25 participants had to come to a check-in center every day at
7:00 a.M. For one week. They were given various amounts of alcohol. Each day, each
participant would flip a coin to determine if they also took Tylenol with their alcohol. They
found that their BAC was 25% higher on days when they were given Tylenol with their
, alcohol than when they drank alcohol alone. This is an example of a(n) - ANS-matched
sample design.
A sample of 92 observations is taken from an infinite population. The sampling distribution of
is approximately - ANS-normal because of the central limit theorem.
A seasonal pattern: - ANS-occurs when a time series plot exhibits a repeating pattern over
successive periods.
A simple random sample of size n from an infinite population is a sample selected such that -
ANS-each element is selected independently and is selected from the same population
A simple random sample of size n from an infinite population of size N is to be selected.
Each possible sample should have - ANS-the same probability of being selected
A statistics teacher started class one day by drawing the names of 10 students out of a hat
and asked them to do as many pushups as they could. The 10 randomly selected students
averaged 15 pushups per person with a standard deviation of 9 pushups. Suppose the
distribution of the population of number of pushups that can be done is approximately
normal. Which of the following statements is true? - ANS-A t distribution should be used
because σ is unknown.
A student wants to determine if pennies are really fair, meaning equally likely to land heads
up or tails up. He flips a random sample of 50 pennies and finds that 28 of them land heads
up. What are the appropriate null and alternative hypotheses? - ANS-H0: p=.5, Ha:p not =.5.
A time series from which the effect of season has been removed by dividing each original
time series observation by the corresponding seasonal index is called a: -
ANS-deseasonalized time series.
A time series method that is used to separate or decompose a time series into seasonal,
trend, and irregular components is called: - ANS-Time series decomposition.
A variable used to model the effect of categorical independent variables is called a(n) -
ANS-Dummy Variable
All of the following are true about qualitative forecasting methods except - ANS-they assume
that the pattern of the past will continue into the future.
All things held constant, which interval will be wider: a confidence interval or a prediction
interval? - ANS-Prediction interval
An approximate value of a population parameter that provides limits and believed to contain
the value of the parameter is known as - ANS-the interval estimate.
An F test, based on the F probability distribution, can be used to test for - ANS-Significance
in regression.
An observation that has a strong influence or effect on the regression results is called a(n) -
ANS-Influential observation.
Applications of hypothesis testing that only control for the Type I error are called -
ANS-significance tests.
As a rule of thumb, the sampling distribution of the sample proportion can be approximated
by a normal probability distribution when - ANS-n(1 - p) ≥ 5 and np ≥ 5.
As the number of degrees of freedom for a t distribution increases, the difference between
the t distribution and the standard normal distribution - ANS-becomes smaller.
As the sample size increases, the margin of error - ANS-decreases.
As the test statistic becomes larger, the p-value - ANS-becomes smaller.
Cluster sampling is - ANS-a probability sampling method.
Correlation in the errors that arises when the error terms at successive points in time are
related is called - ANS-autocorrelation.
Doubling the size of the sample will - ANS-reduce the standard error of the mean