Descriptive Statistics

Question 1

What is central tendency in statistics?

Answer 1

Central tendency refers to the middle of a dataset, representing its center or typical value

Question 2

What are the three main measures of central tendency?

Answer 2

Mean (μ) – The average value

Median (Md) – The middle value when data is ordered

Mode (Mo) – The most frequently occurring value

Question 3

How do you calculate the mean?

Question 4

How do you determine the median?

Question 5

What is the mode and when is data bimodal or multimodal?

Answer 5

The mode is the most frequently occurring value in a dataset

Bimodal: Two modes exist

Multimodal: More than two modes exist

Question 6

What are percentiles?

Answer 6

Percentiles divide ordered data into 100 equal parts, indicating the percentage of values below a certain point

Question 7

What are quartiles and their relation to percentiles?

Answer 7

Q1 (25th percentile) – Lower quartile (median of the lower half)

Q2 (50th percentile) – The median of the dataset

Q3 (75th percentile) – Upper quartile (median of the upper half)

Question 8

How is the interquartile range (IQR) calculated?

Answer 8

IQR=Q3−Q1

Question 9

What is a potential outlier based on IQR?

Answer 9

A value is an outlier if it is:

Morethan1.5×IQRbelowQ1oraboveQ3

Question 10

What are the key measures of variation?

Answer 10

Range – Difference between max and min values

Variance (σ²) – The average squared deviation from the mean

Standard Deviation (σ) – The square root of variance, measuring data spread

Question 11

How do you interpret standard deviation?

Answer 11

A small standard deviation means values are close to the mean

A large standard deviation means values are more spread out