Explanation

The first moment about the mean measures the average deviation from the mean, which is always zero.

This is because the sum of deviations from the mean cancels out.

Explanation

A normal distribution is symmetrical and has a bell-shaped curve.

It represents data that clusters around a central mean.

Explanation

Mean of a binomial distribution is given by:

  Mean = n × p

So, Mean = 4 × 0.5 = 2

Explanation

Two events A and B are independent if the occurrence of one does not affect the occurrence of the other.

This is mathematically defined as:

  P(A ∩ B) = P(A) × P(B)

Explanation

Mutually exclusive events cannot happen at the same time.

So, P(A or B) = P(A) + P(B) when A and B are mutually exclusive.

Explanation

Number of absences is a countable quantity (0, 1, 2, ...), so it's discrete data.

Discrete data deals with whole numbers, not fractions or decimals.

Explanation

1. Descriptive Statistics:

• Deals with summarizing and presenting data (e.g., charts, averages).

2. Inferential Statistics:

• Involves making predictions or inferences about a population based on a sample.

Explanation

Given numbers: 20, 26, 40, 36, 23

Step 1: Add them

20 + 26 + 40 + 36 + 23 = 145

Step 2: Divide by the number of values (5)

145 ÷ 5 = 29

Explanation

The third quartile (Q3) is the value below which 75% of the data falls.

Quartiles divide data into four equal parts, and Q3 marks the 75th percentile.

Additional Information:

Quartiles divide an ordered data set into four equal parts (quarters). We use subscript notation to label the quartiles: Q1, Q2, and Q3.

The first quartile, Q1, is 1/4 (or 25%) of the way through the data – the lower quartile.

The second quartile, Q2, is 1/2 (or 50%) of the way through the data – the median.

The third quartile, Q3, is 3/4 (or 75%) of the way through the data – the upper quartile.

Example data:

3, 4, 4, 5, 6, 8, 10

LQ (Q1): 4

Median (Q2): 5

UQ (Q3): 8

Explanation

The coefficient of variation (CV) is defined as:

(Standard Deviation / Mean) × 100

This formula expresses the standard deviation as a percentage of the mean.