It's 180-50-50=180-100=80°
Option D
Stratification is the splitting of data into case-specific tables is true.
<u>Explanation:</u>
Stratification is a method or configuration of layers, groups, or sections. Stratification intends to classify data/characters/objects into distinct groups or layers. Stratification consists of splitting the group into subsets (named strata) within individual of which an autonomous sample is chosen.
Stratified sampling in statistics is applied to highlight contrasts within groups in a population, as objected to simple random sampling. Stratification is the part of something, primarily society, into various groups or layers.
Answer:
im gonna guess b
Step-by-step explanation:
sry if wrong
Given:
A solution of 60% fertilizer is to be mixed with a solution of 21% fertilizer to form 234 liters of a 43% solution.
To find:
The quantity of the 60% solution in the mixture.
Solution:
Let x be the quantity of the 60% solution and y be the quantity of the 21% solution.
Quantity of mixture is 234. So,

...(i)
The mixture has 43% fertilizer. So,

Multiply both sides by 100.
...(ii)
Using (i) and (ii), we get




Divide both sides by -39.


Putting this value in (i), we get


Therefore, 132 liters of the 60% solution must be used.