SaiBook.us SAT-2

Lesson Example Discussion Quiz: Class Homework

Example

Title: One Variable Data

Grade: 1400-a Lesson: S4-L1

Explanation: The best way to understand SAT-2 is by looking at some examples. Take turns and read each example for easy understanding.

Examples:

Dataset A consists of the heights of 58 buildings and has a mean of 26 meters.
Dataset B consists of the heights of 40 buildings and has a mean of 59 meters.
Dataset C consists of the heights of 98 buildings from datasets A and B.
What is the mean, in meters, of dataset C?

Step 1a

Data set A: 58 buildings
Data set B: 40 buildings
Data set C: 98 buildings (combined total of A and B)

Explanation: Here, we discuss A, B, and C buildings.

Step 1b

Dataset A:
\$"Total height of A" = "mean of A" \times "number of buildings in A" = 26 "meters" \times 58 = 1508 "meters"\$
Dataset B:
\$"Total height of B" = "mean of B" \times "number of buildings in B" = 59 "meters" \times 40 = 2360 "meters"\$

Explanation: Calculate the total height for each dataset.

Step 1c

Total height of C = Total height of A + Total height of B = 1508 meters + 2360 meters = 3868 meters

Total number of buildings in C = number of buildings in A + number of buildings in B = 58 + 40 = 98

\$("Mean height of C") = ("Total height of C")/("Total number of buildings in C")\$

\$(3868 "meters")/ 98 = 39.47 "meters"\$

Explanation: Therefore, the mean height of dataset C is 39.47 meters.