Explanation

A composite index number combines two or more variables into a single index value.

It's often used to measure overall trends, such as in economics or price levels.

Explanation

IQR measures the spread of the middle 50% of the data.

It is calculated as:

  IQR = Q3 – Q1

Explanation

In a histogram, the Y-axis represents the frequencies (i.e., how many data points fall into each class).

The X-axis shows the class intervals (data ranges).

Explanation

Relative frequency is the ratio of the frequency of a class to the total number of observations.

When you add the relative frequencies of all classes, the total must equal 1 (or 100%).

Explanation

An Ogive is a graph that shows cumulative frequencies, either less than or greater than a certain class limit.

It's used to determine medians, percentiles, and quartiles visually.

Explanation

Class boundaries define the exact limits for grouped data.

For a class centered at 25 inches, a typical class width (e.g. 5.2) gives boundaries like 23.50 to 28.70.

Explanation

A standard normal distribution has:

Mean = 0

Standard deviation = 1

So, Variance = (Standard deviation)² = 1² = 1

Explanation

Blood types are non-numeric categories (A, B, AB, O), with no inherent order, so they are nominal.

Since each individual has only one blood type, the data is counted and presented in a discrete frequency distribution.

Explanation

Deciles divide an ordered data set into 10 equal parts.

Each decile represents 10% of the data distribution.

Explanation

To find the mean, add up the values and divide by the number of values:

0 + 0 + 2 + 2 + 2 + 3 + 3 + 8 + 0 + 10 = 30

There are 10 values.

Mean = 30/10 = 3