Stats Final
A numerical measure computed from a sample, such as sample mean, is known as
Sample statistic
A probability sampling method in which we randomly select one of the first k elements and then select every kth (n/N) element thereafter is
Systematic Sampling
If a set has an even number of observations, the median is
The average value of the two middle items when all items are arranged in ascending order
If the data distribution is symmetric, the skewness is
0
The range of probability is
0 to 1, inclusive
The probability of the intersection of two mutually exclusive events
Must always be equal to 0
Two approaches to drawing a conclusion in a hypothesis test are
p-value and critical value
The form of the continuous uniform probability distribution is
rectangular
The difference between the value of the sample statistic and the value of the corresponding population parameter is called the
sampling error
The probability of at least one head in two flips of a coin is
.75
For any continuous random variable, the probability that the random variable takes on exactly a specific value is equal to __________.
0
The t value with 95% confidence and 24 degrees of freedom is
2.064
An experiment consists of three steps. There are four possible results on the first step. Three possible results on the second step, and two possible outcomes on the third step. The total number of experiment outcomes is
24
A magician holds a standard deck of cards and draws one card. The probability of drawing the ace of diamonds is 1/52. What method of assigning probabilities was used
Classical Method
A nonprobability sampling where the sample is selected because it is relatively easy is
Convenience sampling
Data collected at the same, or approximately the same, point in time are _______ data
Cross- sectional
A tabular method that can be used to summarize the data on two variables simultaneously is called
Crosstabulation
The summaries of data, which may be tabular, graphical, or numerical, are referred to as
Descriptive Statistics
The ______ denotes the number of standard deviations Xi is from the mean
Z-score
A Type I error is committed when
a true null hypothesis is rejected
statistical inference
the process of drawing inferences about the population based on information taken from the sample
Larger values of the standard deviation result in a normal curve that is
wider and flatter
The sum of the relative frequencies for all classes will always equal
1
Which of the following values of r indicates the strongest correlation
-.9
An important numerical measure related to the shape of a distribution is the
Skewness
The correlation coefficient ranges from which two values
-1 to +1
Read the t statistic from the table of t distributions and circle the correct answer. A one-tailed test (lower tail), a sample size of 10 at a .10 level of significance; t =
-1.383
A probability sampling in which we randomly select elements within each homogenous group is
Stratified random sampling
For the standard normal probability distribution, the area to the left of the mean is
0.5
The finite correction factor should be used when n/N is greater than
.05
A frequency distribution is a
Tabular summary of a set of data showing the number of items in each of several nonoverlapping classes
A mean computed in such a way that each value is given a weight reflecting its importance is referred to as a
Weighted Mean
There is a 60% chance of getting stuck in traffic when leaving the city. On two separate days what is the probability that you get stuck in traffic both days
.36
Of five letters (A, B, C, D, E) two letters are to be selected at random. How many possible selections are there
10
The "top three" at a racetrack consists of picking the correct order of the first three horses in a race. If there are 10 horses in a particular race, how many outcomes are there
720
Twenty percent of people at a company got food poisoning. What percent of the people did not get food poisoning.
80%
An interval estimate is used to estimate
A Population Parameter
The number of costumers who enter a store during one day is an example of
A discrete random variable
If you are conducting an experiment where the probability of a success is .02 and you are interested in the probability of two successes in 15 trials, the correct probability function to use is the
Binomial probability function
A theorem that allows us to use the normal probability distribution to approximate the sampling distribution of sample means and sample proportions whenever the sample size is larger is known as the
Central Limit Theorem
If arrivals follow a Poisson probability distribution, the time between successive arrivals must follow
Exponential
There is a lower limit but no upper limit for a random variable that follows the _________ probability distribution
Exponential
When sampling without replacement, the probability of obtaining a certain sample is best given by a ( uniform / binomial / Poisson / hypergeometric ) distribution.
Hypergeometric distribution
When the data have the properties of ordinal data and the interval between observations is expressed in terms of a fixed unit of measure, the variable has which scale of measurement? (example-Temperature)
Interval
The coefficient of variation indicates how large the standard deviation is relative to the
Mean
After the data have been arranged from smallest to largest, the value in the middle is called the
Median
The 50th percentile is the
Median
When the data are labels or names used to identify attribute of the elements, the variable has which scale of measurement (example- Gender)
Nominal
The mean, median, mode have the same value for which of the following distributions
Normal
As the degrees of freedom increase, the t distribution approaches the
Normal distribution
When the data are labels or names used to identify an attribute of the elements and the rank of the data is meaningful, the variable has which scale of measurement (example- Class Standing)
Ordinal
Excel's __________ can be used to construct a crosstabulation.
PivotTable Report
In the textile industry, a manufacturer is interested in the number of blemishes or flaws in each 100 ft of material. The probability distribution that has the greatest chance of applying to this situation is the
Poisson
The random variable x is the number of occurrences of an event over an interval of 10 minutes. It can be assumed the probability of an occurrence is the same i n any two time periods of equal length. It is known that the mean number of occurrences in 10 minutes is 5.3. The random variable x satisfies which of the following probability distributions
Poisson
A numerical measure, such as a mean, computed from a population is known as a
Population Parameter
_____ analytics consists of analytical techniques that use models constructed from past data to predict the future or to assess the impact of one variable on another
Predictive
The measure of dispersion that is influenced most by extreme values is the
Range
when the data have the properties of interval data and the ratio of two values is meaningful, the variable has which scale of measurement? (example- Heights)
Ratio
When the results of experimentation or historical data are used to assign probability values, the method used to assign probabilities is referred to as the
Relative Frequency method
Excel's _____ function can be used to compute the expected value of a discrete random variable
SUMPRODUCT
The height and weight are recorded by the school nurse for every student in a school. What type of graph would best display the relationship between height and weight
Scatter diagram
A two-tailed test is performed at 5% level of significance. The p-value is determined to be 0.09. The null hypothesis
Should not be rejected
The highest point of a normal curve occurs at
The mean
The sum of frequencies for all classes will always equal
The number of elements in a data set
Which of the following is an example of quantitative data
The number of people in a waiting line
The collection of all possible sample points in an experiment
The sample space
For a standard distribution, a negative value of z indicates
The z is to the left of the mean
Data collected over several time periods are ______ data
Time series
The relative frequency of a class is computed by
dividing the frequency of the class by the sample size
as sample size increases the
standard error of the mean decreases