Public Health Data Test #2
If we want to be 99% sure that the confidence interval contains the real population value, the type I error level is ___________? 0.05 0.10 0.01 0.005
0.01
Consider the following information: the sample size of a sampled population is 500, the standard deviation of the sample is 14, the observed sample mean is 88, and the hypothesized population mean is 93? Based on this information, what is the sample estimator of the standard error of a mean? 1.60 0.63 14 0.03
0.63
If the average sampled United States population income level per person is $35,000 with a Standard Deviation of $9,000 for the sampled population, and you just got a job and are earning $41,000, how many standard deviations are you away from the mean? -0.6667 0.6667 0.2514 0.7486
0.6667
If you were to add up all of the proportions related to the area under the curve you would get ________ . 0.95 1 0.68 0.99
1
If the standard deviation is 2 and the mean is 10, then what is the coefficient of variation? 5 0.2 500 20
20
When drawing a box-and-whisker plot, the lower hinge represents the ____ percentile and the upper hinge represents the ____ percentile. 75; 50 25;50 25; 75 75; 25
25; 75
If the error of being wrong is 5%, you have selected a ________ confidence interval. 95% 90% 99% 5%
95%
Typically, what percentage of observations in a normal distribution usually fall between 3 standard deviations of the mean. 95% 68% 50.7% 99.7%
99.7%
When measuring the direction and strength of the relationship between two paired sets of quantitative values, it is known as a ________. Variable Mean Standard deviation Linear correlation
Linear correlation
Which of the follow is generally more sensitive or influenced by extreme values or outlier data Mode Mean Median Central tendency
Mean
Which of the following is the most sensitive to extreme values or outliers in the data? Mean Median Mode Range
Mean
The words "change," "rise," "fluctuate," "grow," "decline," "trend," "increase or decrease" are used to determine whether your quantitative message involves a __________________. Box-and- Whisker Chart Time series Normality Pie chart
Time series
A pie chart is better to show the sizes of the groups as parts of the whole sample. True or False
True
Box-and-whisker plots do no provide the precise numerical values that statistical measures like the mean, standard deviation, and the coefficient of skewness do True or False
True
Exploratory variables or covariates are known as dependent variables. True or False
True
The most frequent value in a distribution is know as the ________? Median Mode Standard deviation Mean
Mode
In order to avoid double counting observations into more than one category, categories should be ____________. Jointly exhaustive Real class boundaries Mutually exclusive Mutually inclusive
Mutually exclusive
When a variable is ___________, the order in which bars in a bar chart are arranged doesn't affect interpretation. continuous ordinal nominal paired
Nominal
When the center of the sampling distribution of the statistic falls at zero, we indicate that the __________ is true. Critical Value Alternative hypothesis Null Hypothesis Test Statistic
Null Hypthesis
If the mean is higher than the median, the distribution is positively skewed. True or False
True
If the pot area on a graph is is taller than is wide, it can be deceptive and provide false impression. True or False
True
If we set the alpha to be 0.05 and the associated p-value of from the hypothesis test is 0.001, we would reject the null hypothesis. True or False
True
If you as a researcher need to be sure that a specific set of values or a range of values includes the mean or proportion, then it is important to have a wider confidence interval? True or False
True
If you were to adjust the mean and standard deviation of a distribution, the distribution can be expressed as a function of the standard normal distribution. True or False
True
In a chart, the y-axis is the vertical dimension and the x-axis is the horizontal dimension? True or False
True
In applications of statistics, we observe a sample in order to make conclusions of an entire population from which the sample was taken. True or False
True
Numbers that represent quantitative values, as opposed to those that are merely identifiers, should always be aligned to the right. True or False
True
One of the key assumptions of hypothesis testing is that the sample is selected from simple random sampling. True or False
True
Quantitative values can be represented in graphs using points, lines, bars, boxes, shapes with varying 2D areas, and shapes with varying color intensities. True or False
True
Reference lines can be used to make a break point in a series of categorical subdivisions. True or False
True
Skewness deals with whether the central tendency is in the middle of the distribution, while modality asks how many central tendencies are there. True or False
True
Which one of these font types is not recommended to be used in a table because of its poor legibility Georgia Poplar std black Verdana Times New Roman
Poplar std black
Subtracting the lowest score from the highest score in a sample is known as the _________. Central tendency Range Mean Interquartile range
Range
The central tendency and dispersion are the two most specific aspects of the shape of frequency distributions. True or False
True
Then computing the z-score, the sample mean is subtracted from the individual score or case in the numerator? True or False
True
Trend lines are used to summarize the overall pattern that fits in a set of values. Trend lines are most useful when applied to scatterplots. True or False
True
When a distribution such as a normal distribution has a single area where relative frequencies are highest, it is know as unimodal. True or False
True
When calculating the median, it is important to rank the observation from highest to lowest and select the observation in the middle. True or False
True
When writing a report to communicate data, text should be included answer the following questions: What? When? Who? Where? True or False
True
You should not use inferential statistic methods for non-probability samples. True or False
True
When computing the coefficient of variation, the standard deviation is divided by the _________? mean median 100 variance
mean
If there are three modes in a distribution, the distribution is ________. multimodal symmetrical bimodal unimodal
multimodal
In a scatter plot, when points are hidden or overlapped by other points to the degree that they can't be distinguished, this is known as __________. abnormal distribution over plotting grouping confounding
over plotting
When data is skewed to the left or the right, the mean is different than the median. In this case, when reporting data, you should _____________? report only the mean since it is the average of the data report the mode since the mean and the median are different report only the median, since it is the score of the cases at the 50th percentile of ranked data report both the mean and the median
report both the mean and the median
The peak or the mode of a normal distribution is _______. to the right of the median to the left of the median left of the 25% quartile right in the middle
right in the middle
The _________ is the most common statistic for summarizing the amount of dispersion in the data. interquartile range standard deviation mean median
standard deviation
When a population is divided into various groups or categories, this division is known as a _________. probability sample nonprobability sample sampling distribution trata
strata
When formatting dates in tables, which of the following is NOT recommended for a table: Spell out the entire month Express months as a two digit number Express day using two digits Express months as a three character word
Spell out the entire month
Subtracting the lowest value from the highest value in your data is know as the ______? Median Spread Standard deviation Mode
Spread
_________ is a concept used to come up with the best estimate about the value of a population parameter through a sample statistic? Confidence interval Statistical inference Probability sample Nonprobability sample
Statistical inference
When a scatter plot goes downward from left to right with observations tightly grouped around a straight line, the relationship is known as a _________. a. Strong positive correlation. b. Strong negative correlation Weaker negative correlation No correlation
Strong negative correlation
When assessing the distribution and the skewness, which is true of a positive skew. The long tail is toward the right, or higher values, the distribution is positively skewed. The long tail is toward the left, the higher values, the distribution is not skewed. The long tail is the right, the lower values, the distribution is positively skewed. The long tail is toward the left, the lower values, the distribution is positively skewed.
The long tail is toward the right, or higher values, the distribution is positively skewed.
The interquartile range can be achieved by subtracting ____________. the lowest percentile from the highest percentile the 25th percentile from the 75th percentile. the 5th percentile from the 95th percentile the 50th percentile from the 75th percentile
the 25th percentile from the 75th percentile.
If there are two cases adjacent to the 50th percentile that have different scores and you are using the median with interval-level data as your central tendency measure, you would define the median as _________. the mean of all of the values in the distribution the lowest of the two values the highest of the two values the average of the two values
the average of the two values
When computing the mean, the denominator (or the bottom) of the formula is ____________. the sample size, N the average the sum of all of the observations the median
the sample size, N
The alpha in hypothesis testing is ________. the type II error always 0.05 the type I error the null hypothesis
the type I error
About 95% of cases fall within ________ standard deviations above and below the mean? one two three four
two
A normal distribution has a __________ shape. bimodal multimodal unimodal asymmetrical
unimodal
When a researcher says the average squared distance of cases from the mean is 100 units, he/she is talking about the __________? mean of the data standard deviation square root of the data variance of the data
variance of the data
Ordinal variables are best summarized using a pie chart. True or False
False
The Z distribution is a normal distribution with a mean of 1 and standard deviation of zero. True or False
False
The divided line between the region where we accept the null and where we reject it is known as the rejection region? True or False
False
The normal approximation is the best approximation of the shape of a sampling distribution, especially when the sample size is small? True or False
False
The range can not be affected by extreme scores or outliers? True or False
False
The type II error or alpha level is the probability that the population parameter falls within the defined confidence interval. True or False
False
There are only two tailed versions of the alternative hypothesis. True or False
False
When considering Gestalt's Principles of Visual Perception, continuity means that objects share similar attributes such as color and are perceived as a group. True or False
False
When looking at a distribution graph, the median will always be pulled away from the mean in the direction of the longer tail. True or False
False
A distribution with a higher peak than expected compared to a normal curve is called _____________. Kurtosis Leptokurtic Platykurtic bimodal
Leptokurtic
Consider the following information: the sample size of a sampled population is 100, the standard deviation of the sample is 10, the observed sample mean is 8, and the hypothesized population mean is 6. Based on this information, what is the test statistic (t)? 0.2 6.0 -1.99 1.99
1.99
When a researcher wishes to describe how different a distribution in one population is from another population, an index of qualitative variation is generally the best statistic to use. True or False
False
There are a total of 1,500 people in the population surveyed. Of the 1,500 total people, 816 are married, 150 are widowed, 199 are divorced, 45 are separated, and 290 have never been married. What is the proportion of people who have never been married? 290 0.193 5.172 0.00193%
0.193
If the standard deviation of a set of cases in a sample is 14 and the sample size of a simple random sample is 123, what is the standard deviation of the sampling distribution. 8.79 0.11 1.26 14
1.26
Line graphs that use hues shows lines that are not clearly distinct from one another. True or False
False
What is the mean of the following numbers: 3, 7, 23, 37, 17, 8 ? 12.5 95 0.06 15.83
15.83
What is the median of the following distribution: 3, 23, 8, 7, 37, 17 ? 8 15.83 17 12.5
17
Which of the following best represent the measurement for a nominal variable? 1 = small, 2= medium, 3= large, 4= gigantic 1= white, 2= asian, 3= black, 4=hispanic a= >=0 to <100, b= >=100 to <200, c= >=200 to <300, d= >=300 to <400
1= white, 2= asian, 3= black, 4=hispanic
The average time for all track and field runners in the state to run a mile is 7 minutes with a standard deviation of 1.5 minutes. You set a goal for yourself to consistently run the mile in a range of 6 minutes and 7.5 minutes. What percent of the population would you expect to run the mile within these time intervals? 33.34% 37.79% 11.93% 66.67%
37.79%
If the variance of the data is 25, then the standard deviation is ________? 5 Can not be determined because there is not enough information 50 625
5
If the significance level for a two-tailed test is 0.05, this means that _______________? 2.5% of the samples might have means that are as far or further away from the null hypothesis about the mean just by chance. 95% of the samples might have means that are as far or further away from the null hypothesis about the mean just by chance. Correct Answer 5% of the samples might have means that are as far or further away from the null hypothesis about the mean just by chance. 0.05% of the samples might have means that are as far or further away from the null hypothesis about the mean just by chance.
5% of the samples might have means that are as far or further away from the null hypothesis about the mean just by chance
What is the mode in the following distribution of numbers: 3, 67, 67, 45, 88, 98, 34, 88, 65, 67, 11, 6, 4, 3, 100, 55. 88 67 3 50
67
If the average sampled United States population income level per person is $35,000 with a Standard Deviation of $9,000 for the sampled population, and you just got a job and are earning $41,000, what percentile does your income fall into? 33.33% 25.14% 74.86% 66.67%
74.86%
A variable whose numerical values can be broken down or sub-divided into finer units almost indefinitely is know as a ________ variable. Discrete Answer Continuous Concrete You Answered Independent
Continuous
Consider the following words: "increases with," "decreases with," "varies with," "affected by," "caused by". These are words that indicate a ________________. Skewness Normal distribution Correlation Frequency
Correlation
Trend lines are often included in scatter plots to show the pattern of __________. Skewness Statistical inference Correlation where the mean is located
Correlation
Consider the following words: "difference," "relative to," "variance," "plus or minus". These words express ______________. Time series relationships Normality Relationships Deviation relationships Ranking relationships
Deviation relationships
95% of the cases consist of scores that fall within 1 standard deviation of the mean, in other words with a z-score of -1.0 and 1.0. True or False
False
A time series graph displays quantitative values among a single, sequential points in time. True or False
False
An important distinguishing characteristic of a histogram from a bar chart is that the bars do not touch one another in a histogram? True or False
False
Bar charts can only be presented vertically. True or False
False
Box-and-whisker plots are used for nominal or grouped ordinal data. True or False
False
In a graph, axes provide scales that are only categorical and not quantitative, used to label and assign values to visual objects. True or False
False
In most cases, you should not keep the value zero in your quantitative scale, and if you do include the value zero you must alert the reader. True or False
False
In order to compute the mean, you must first rank the observations from lowest to highest? True or False
False
Which graphical technique is associated with the following attributes: displays a single distribution and the bars do not have spaces between them which suggests the continuous nature rather than the discrete nature of the scale. Histogram Pie chart Scatter plot Bar chart
Histogram
__________ is the preferred means for arranging for arranging data into columns and rows within a table. Dash lines Underlines Commas White space
White Space
Which of the 8 types of relationships do professionals typically use graphs to display? deviation, ranking, part-to-whole, correlation, geospatial, nominal comparison, time series, distribution chi-squared, ranking, part-to-whole, correlation, geospatial, nominal comparison, time series, distribution deviation, ranking, part-to-whole, correlation, geospatial, nominal comparison, normality, distribution deviation, ranking, part-to-whole, correlation, geospatial, nominal comparison, time series, statistical
deviation, ranking, part-to-whole, correlation, geospatial, nominal comparison, time series, distribution
You can convert a percentage into a proportion by ____________ (Hint: See page 29 for the formula and think about it). moving the decimal two places to the right dividing by 100 taking the square root multiplying by 100
dividing by 100
When you first select a subpopulation with a known probability, and then select cases from each selected subpopulation with a known probability, this is known as a __________ sample. cluster stratified nonprobability non-inferential
cluster
