hevdb s nd Flashcards
What are measures of location?
Measures of location indicate at what numerical values certain characteristic points of the distribution are located.
What is the mean of a data set?
The mean is commonly referred to as the average of all the data values.
What is a sample statistic referred to as?
A sample statistic is referred to as the point estimator of the corresponding population parameter.
What is the formula for the sample mean?
Sample Mean = Sum of the values of the n observations / Number of observations in the sample.
What is the population mean denoted as?
The population mean is denoted as m.
What is the weighted mean?
The weighted mean is computed by giving each data value a weight that reflects its importance.
What is the formula for computing the weighted mean?
Weighted Mean = Σ (y_i * W_i) / Σ W_i.
What is the median?
The median is the value in the middle when the data items are arranged in ascending order.
How is the median calculated for an odd number of observations?
Position of the median: i = (n + 1) / 2; Value of the median: Me = y_i.
How is the median calculated for an even number of observations?
Position of the median: i = (n + 1) / 2; Value of the median: Me = (y_i-0.5 + y_i+0.5) / 2.
What is the mode of a data set?
The mode is the value that occurs with greatest frequency.
What is a bimodal data set?
A bimodal data set has exactly two modes.
What are percentiles?
Percentiles are cut-off values that separate the lower p% of the data from the upper (100 - p)%.
What is the formula to compute the position of the pth percentile?
i = (p / 100) * n.
What is the first quartile?
The first quartile is the 25th percentile.
What is the second quartile?
The second quartile is the 50th percentile, also known as the median.
What is the third quartile?
The third quartile is the 75th percentile.
What is the five-number summary?
The five-number summary includes the smallest value, first quartile, median, third quartile, and largest value.
What is a box plot?
A box plot visualizes the five-number summary and displays the interquartile range.
What is the interquartile range (IQR)?
The IQR is calculated as the difference between the first and third quartiles: IQR = Q3 - Q1.
What defines the normal range in a box plot?
The normal range is defined as the interval between the lower and upper limits determined using the IQR.
True or False: The median is preferred over the mean in data sets with extreme values.
True.
Fill in the blank: The _______ of a data set is the value that occurs with greatest frequency.
mode
What is the formula for the sample mean for grouped data?
Sample Mean = Σ (f_i * M_i) / Σ f_i.
What is a multmodal data set?
A multimodal data set has more than two modes.
What is the 90th percentile in the given apartment rents example?
The 90th percentile is 585.
What is the formula for calculating the weighted mean for grouped data?
Weighted Mean = Σ (f_i * M_i) / Σ f_i where f_i is frequency and M_i is the midpoint.
What does IQR stand for?
Interquartile Range
How is IQR calculated?
IQR = Q3 - Q1
What is the formula for calculating the lower limit in a box plot?
Lower Limit = Q1 - 1.5 × IQR
What is the formula for calculating the upper limit in a box plot?
Upper Limit = Q3 + 1.5 × IQR
What is considered as normal range in data analysis?
The interval between the lower and the upper limits
What is the IQR for the given data if Q3 is 525 and Q1 is 445?
80
What are outliers in data?
Data outside the normal range
What are the lower and upper limits calculated from Q1 and Q3 in the example?
[325, 645]
What does a box plot use to represent outliers?
A suitable symbol, e.g., an asterisk (*)
True or False: There are outliers in the apartment rent data provided.
False
What are whiskers in a box plot?
Dashed lines drawn from the ends of the box to the smallest and largest data values within the normal range
Fill in the blank: The smallest value in the normal range is _______.
425
Fill in the blank: The largest value in the normal range is _______.
615
