Answer:
The shaded area is 314.2 cm²
Step-by-step explanation:
Here we note that the shape consists of two small circles and one larger circle
The diameter of the larger semicircle is subtended by the two smaller semicircles, the small semicircle closer to the left of the internal circumference of the larger semicircle is shaded one while the one on the right is without color,
Therefore,
Diameter of larger semicircle = 2 × 10 = 20 cm
Based on the diagram, the shaded area is observed to be;
Shaded area = Area of semicircle formed by larger diameter or 20 cm + Area area formed by the small semicircle close to the right of the internal circumference of the larger semicircle - Area area formed by the other smaller semicircle
Since the diameter and therefore the areas of the two small semicircles are equal, we have;
Shaded area = Area formed by the complete larger semicircle = Area of semicircle formed by larger diameter or 20 cm
∴ Shaded area = π·D²/4 = π×20²/4 = 100×3.142 cm² = 314.2 cm².
Answer:
a) cluster sampling
Step-by-step explanation:
In cluster sampling method, each member of a population is assigned to one and only one group.This means clusters are formed through probability method usually a simple random sampling.The participants in the clusters are the only one to be surveyed.
In this example, simple random sampling is used to identify 12 home rooms(cluster) where a group of 20 students (participants) in each room is given the survey.
This is not correct. It is not taking into account the 150 employees.
