1. 1 Displaying Distributions with Graphs 1. In statistics, individuals are the objects described by a set of data, they can be people or animal or things. 2. In statistics, a variable is any characteristic of an individual. A variable can take different values for different individuals. 3. Exploratory data analysis is an examination where statistical tools and ideas can help you examine data in order to describe their main features. 4. A categorical variable places an individual into one of several groups or categories while a quantitative variable takes numerical values for which arithmetic operations such as adding and averaging make sense. 5. It is useful to use a bar chart when dealing with counts 6. It is useful to use a pie chart when …show more content…
The median is resistant to extreme observations because its based on the middle one or two observations of the ordered list, while the mean is nonresistant due to the influence of few extreme observations. 5. In stats, spread is a way to measure the variability of the observations around the center. 6. To calculate Q1 and Q3 , you must first arrange the observations in increasing order to find the median, Q1 is the median of the observations whose position in the list is to the left of the overall median, Q3 is the median of the observations whose position in the list is to the right of the overall median. 7. The five-number summary is minimum, Q1, median, Q3, maximum 8. Standard deviation measures spread. 9. The relationship between variance and standard deviation is that the standard deviation(s) is the square root of the variance s2. 10. Standard deviation equals zero when there is no spread, that only happens when all observations have the same value. 11. Standard deviation is non resistant to extreme observations because strong skewness or a few outliers can make the standard deviation very large. 2.1 Density Curves and the Normal Distributions A density curve is a curve that is always above or on the x-axis and one that has its area exactly one underneath that
Standard Deviation for the mean column is 0.476Standard Deviation for the median column is 0.754Standard deviation for the mean column has least variability
-The shape of both data sets fall within the rule of thumb estimate and that actual standard deviation. There is a much high range for both and that is because there are several data samples that fall outside of the standard deviation.
and SD are _______________________ statistics. The mean is the measure of Central tendency of a distribution while SD is a measure of dispersion of its scores. Both X and SD is descriptive statistics.
deviations. That is, unusual values are either less than μ - 2σ or greater than μ + 2σ.
1) Which of the following measures of central location is affected most by extreme values? A. MeanB. MedianC. Mode D. Geometric mean
* 7. The mean (Median) is a measure of location (central tendency) of a distribution while the SD is a measure of scale (variability) of its scores. Both mean and SD are measure of descriptive statistics.
Standard deviation is a way of visualizing how spread out points of data are in a set. Using standard deviation helps to determine how rare or common an occurrence is. For example, data points falling within the boundaries of one standard deviation typically account for about 68% of data and those between (+/-)1 standard deviation and (+/-)2 standard deviations make about 27% combined. This can be better visualized by using a bell graph. Using the mean and standard deviation, the points where standard deviations occur can be drawn on the graph to better understand which data is rare and which is common.
c) Is there a high probability that the mean and standard deviation of your sample are consistent
Both graphs will have the same shape (they will both be bell-shaped) and they will be centered at the same place (the common mean). The graph of the variable with the smaller standard deviation will be narrower and taller than the other graph.
Variable Body Style is qualitative, variable Weight is continuous, variable Number of Seats is discrete
5. The standard deviations of the groups are different between these two data sets. This implies that both girls and the boys groups have a large variability in their data. The reason is that the standard deviation for boys is 5.9 and the standard deviation for girls is 5.0. This means the data has a wide range of data within the mean.
spread of scores from the mean (Burns & Grove, 2007). The larger the value of the standard deviation for study variables, the greater the dispersion or variability of the scores for the variable in a
Two sets of data both have a mean of 17. Set A has a standard deviation of 3.5. Set B has a standard deviation of 6.8. Explain specifically what the different standard deviation measurements tell you as a researcher about the two data sets?
I will be doing a bar graph on the amount of candy produce daily. “A bar graph consists of bars representing frequencies (or relative frequencies) for particular categories” (Bennett,2012, p. 87).
But If I would choose only one measure of center I would choose the median because it is resistant to outliners. And if I would choose one measure of spread I would choose the standard deviation because standard deviation explain how the data set is separated around the mean, as a result I can understand the spread of the data, and draw conclusions and estimations.