lecture recording on 15 January 2025 at 10.13.16 AM

Sales Data Overview

• October Sales: $35,000

• November Sales: $62,500

Sales Question Examples

• If asked about February sales, reference the data directly.

• For example, in January, sales were $34,000.

Line Graph Explanation

• Definition: Visual representation showing relationship between variables, such as rainfall in two cities.

• Key Observations:

  • Two lines represent two different cities.

  • Questions may include comparisons like "In June, how much more did City 1 have in rainfall than City 2?"

• Calculating Differences:

  • Example: If City 1 has 1.4 inches and City 2 has 0.2 inches, the difference is:

    • 1.4 - 0.2 = 1.2 inches.

Data Type Definitions

• Quantitative Data: Also known as numerical data, represented by numbers that can be measured.

• Qualitative Data: Also referred to as categorical data, describing non-numerical attributes (e.g., favorite colors).

Bar Chart Explanation

• Bar Charts: Can be vertical or horizontal, showing preferences (e.g., students' favorite colors).

• Example Question: "How many students like blue the most?"

  • Expected answer: 7 students preferred blue.

Stem and Leaf Graph

• Definition: A way to organize data showing the tens and ones place for values, condensing numerical data.

• Key Example:

  • The number 37 is represented in the stem-and-leaf format by having 3 in the tens place and 7 in the ones place.

• Data Organization: Provides a visual where similar values are grouped, such as:

  • 30, 33, 34, etc. shown broadly for easier reference.

Interpreting Stem and Leaf Data

• Largest Value: Identified in the graph is 72.

• Total Data Values: Count each number present in the stem-and-leaf; do not count the stems themselves.

• Smallest Value in Last Class: For the last class, the smallest value is 63.

• Frequency Finding: For classes with the most values, count the numbers in that section. In one example, it totals to 15 values.

• Counting Values Greater than 40: Tally the numbers directly above 40, resulting in a total of 21 values.