Which measure of central tendency represents the most frequently occurring value in a dataset?
Mode
Median
Mean
Range
For grouped data, how is the modal class typically identified?
The class with the highest frequency.
The class with the highest frequency density.
The class with the widest interval.
The class containing the median.
When a dataset contains extreme values (outliers), which measure of central tendency is generally least affected?
Mean
Median
Mode
Range
The range of a dataset is defined as the numerical difference between which two values?
The upper quartile and the lower quartile.
The mean and the mode.
The largest and smallest values.
The standard deviation and the variance.
To estimate the median from a cumulative frequency graph for a dataset with a total frequency of 'n', which position is typically used?
The (n+1)/2 th value.
The n/2 th value.
The (n+1)/4 th value.
The (3n)/4 th value.
Which of the following statements about the mean of a dataset is true?
A) It is always unaffected by extreme values.
B) It takes into account all data values.
C) It is only used for qualitative data.
D) All of the above
If every value in a dataset is increased by a constant amount, which measure of spread remains unchanged?
Range
IQR
Standard deviation
All of the above
What does a high standard deviation indicate about a set of data values?
The values are tightly clustered around the mean.
The values are widely spread out from the mean.
The data is qualitative.
The mean is much larger than the median.
The interquartile range (IQR) measures the spread of what portion of the data?
A) The entire dataset.
B) The top 25%.
C) The middle 50%.
D) The bottom 75%.
Given the dataset: 12, 18, 15, 20, 14, 16, 13. What is the interquartile range (IQR)?
4
5
6
7
The following stem-and-leaf diagram shows 13 grouped values. What is the interquartile range (IQR) of this data?
10
12
14
16
If the variance of X is 25, what is its standard deviation?
A) 25
B) 5
C) 0.25
D) 625
For a dataset of 10 values, Σx is 150 and the sum of the squares of the values (Σx²) is 3250. What is the standard deviation of this dataset?
5
10
15
25
A dataset has a standard deviation of 8. If every value in the dataset is increased by 3, what is the new standard deviation?
3
8
11
Cannot be determined
Adding a constant to every data point shifts the entire dataset but does not change its spread. Therefore, measures of spread like______ remain unchanged
range
standard deviation
interquartile range
variance
Var( )=16, Var( )=______
16
32
64
256
If the standard deviation of a dataset is 4, what is its variance?
Two brands of light bulbs, A and B, have the same mean lifespan. SD(A)= 50 hours, and SD(B)= 10 hours. What does this suggest about the lifespans of the bulbs?
Brand A bulbs are more consistent.
Brand B bulbs are more consistent.
Both brands have equally consistent lifespans.
Standard deviation does not relate to consistency.
A set of data has a standard deviation of 10. If each data value is divided by 5, what is the new standard deviation?
2
5
10
50
If data values are multiplied or divided by 7, the standard deviation is multiplied or divided by the absolute value of _____
For the data set: 2, 4, 6, 8. What is the variance?
2
4
5
6