Which of the following is NOT a descriptor of a normal distribution of a random? variable?
The graph is centered around 0.
Which of the following groups of terms can be used interchangeably when working with normal? distributions?
?areas, probability, and relative frequencies
A continuous random variable has a? _______ distribution if its values are spread evenly over the range of possibilities.
uniform
Which of the following is NOT a requirement for a density? curve?
the graph is centered around 0
Which of the following does NOT describe the standard normal? distribution?
The graph is uniform.
Finding probabilities associated with distributions that are standard normal distributions is equivalent to? _______.
finding the area of the shaded region representing that probability.
The notation ?P(z<?a) denotes? _______.
the probability that the z-score is less than a.
Which of the following would be information in a question asking you to find the area of a region under the standard normal curve as a? solution?
A distance on the horizontal axis is given
What requirements are necessary for a normal probability distribution to be a standard normal probability? distribution?
The mean and standard deviation have the values of u=0 and o=1.
Which of the following is not? true?
A? z-score is an area under the normal curve.
Where would a value separating the top? 15% from the other values on the graph of a normal distribution be? found?
the right side of the horizontal scale of the graph
What conditions would produce a negative? z-score?
a? z-score corresponding to an area located entirely in the left side of the curve
If you are asked to find the 85th? percentile, you are being asked to find? _____.
a data value associated with an area of 0.85 to its left
?_____________ is the distribution of all values of the statistic when all possible samples of the same size n are taken from the same population.
The sampling distribution of a statistic
Which of the following is NOT a property of the sampling distribution of the sample? mean?
The distribution of the sample mean tends to be skewed to the right or left.
Which of the following is NOT a property of the sampling distribution of the? variance?
The distribution of sample variances tends to be a normal distribution.
?_____________ is the distribution of sample? proportions, with all samples having the same sample size n taken from the same population.
The sampling distribution of the proportion
Which of the following is a biased? estimator? That? is, which of the following does not target the population? parameter?
Median
Which of the following statistics are unbiased estimators of population? parameters?
-Sample proportion used to estimate a population proportion.
-Sample variance used to estimate a population variance.
-Sample mean used to estimate a population mean.
The? _______ tells us that for a population with any? distribution, the distribution of the sample means approaches a normal distribution as the sample size increases.
Central Limit Theorem
The standard deviation of the distribution of sample means is? _______.
stand dev/ sqr root of n
Which of the following is NOT a conclusion of the Central Limit? Theorem?
The distribution of the sample data will approach a normal distribution as the sample size increases.
The? _______ states that? if, under a given? assumption, the probability of a particular observed event is exceptionally small? (such as less than? 0.05), we conclude that the assumption is probably not correct.
Rare Event Rule for Inferential Statistics
Which of the following is not a commonly used? practice?
If the distribution of the sample means is normally? distributed, and n>?30, then the population distribution is normally distributed.
Which of the following is NOT a procedure for determining whether it is reasonable to assume that sample data are from a normally distributed? population?
Checking that the probability of an event is 0.05 or less
A? _____________ is a graph of points? (x,y) where each? x-value is from the original set of sample? data, and each? y-value is the corresponding? z-score that is a quantile value expected from the standard normal distribution.
normal quantile plot
Which of the following is NOT true in regards to using a normal quantile plot to determine whether or not a distribution is? normal?
If the plot is? bell-shaped, the population distribution is normal.
If you select a simple random sample of? M&M plain candies and construct a normal quantile plot of their? weights, what pattern would you expect in the? graphs?
Approximately a straight line.
Sample data for the arrival delay times? (in minutes) of airlines flights is given below. Determine whether they appear to be from a population with a normal distribution. Assume that this requirement is loose in the sense that the population distribution
?No, because the histogram of the data is not bell? shaped, there is more than one? outlier, and the points in the normal quantile plot do not lie reasonably close to a straight line.
A critical? value, z Subscript alpha?, denotes the? _______.
z dash score with an area of alpha to its right.
Which concept below is NOT a main idea of estimating a population? proportion?
Using a sample statistic to estimate the population proportion is utilizing descriptive statistics.
Which of the following groups has terms that can be used interchangeably with the? others?
?Percentage, Probability, and Proportion
A? _______ is a single value used to approximate a population parameter.
point estimate
Which of the following is NOT true of the confidence level of a confidence? interval?
There is a 1-alpha ?chance, where alpha is the complement of the confidence? level, that the true value of p will fall in the confidence interval produced from our sample.
Which of the following is NOT an observation about critical? values?
A critical value is the area in the? right-tail region of the standard normal curve.
Which of the following is NOT a requirement for constructing a confidence interval for estimating the population? proportion?
The trials are done without replacement.
When analyzing? polls, which of the following is NOT a? consideration?
The sample should be a voluntary response or convenience sample.
Which of the following is NOT needed to determine the minimum sample size required to estimate a population? proportion?
Standard Deviation
A newspaper provided a? "snapshot" illustrating poll results from 1910 professionals who interview job applicants. The illustration showed that? 26% of them said the biggest interview turnoff is that the applicant did not make an effort to learn about the
the confidence level
The number of? _______ for a collection of sample data is the number of sample values that can vary after certain restrictions have been imposed on all data values.
degrees of freedom
Which of the following is NOT a property of the Student t? distribution?
The standard deviation of the Student t distribution is s=1
The? _______ is the best point estimate of the population mean.
sample mean
Which of the following calculations is NOT derived from the confidence? interval?
The population? mean, u=(upper confidence limit) + plus (lower confidence limit)
Which of the following would be a correct interpretation of a? 99% confidence interval such as 4.1 <u<5.6
We are? 99% confident that the interval from 4.1 to 5.6 actually does contain the true value of u
Which of the following is NOT an equivalent expression for the confidence interval given by 161.7<u<189.5
161.7 +-27.8
Which of the following is NOT required to determine minimum sample size to estimate a population? mean?
The size of the? population, N
What does it mean to say that the confidence interval methods for the mean are robust against departures from? normality?
The confidence interval methods for the mean are robust against departures from? normality, meaning they work well with distributions that? aren't normal, provided that departures from normality are not too extreme.
The? _____________ distribution is used to develop confidence interval estimates of variances or standard deviations.
Chi-square
Which of the following is NOT a property of the? chi-square distribution?
The mean of the? chi-square distribution is 0.
The best point estimate of the population variance stand dev squared is the? _____________.
sample variance, s^2
Which of the following is NOT a requirement of constructing a confidence interval estimate for a population? variance?
The population must be skewed to the right.