Answer:
Grandfather age = 20 * 4 = 80
Step-by-step explanation:
Let Elena age be x
grandfather age is 4x
x + 4x = 100
5x = 100
x = 100/5 = 20 = Elena age
4.3x(3.9 - 8.5) + 2.3y(-6.2 - 9.1)......when x = -2.1 and y = 3.5
4.3x(-4.6) + 2.3y(-15.3)
4.3(-2.1)(-4.6) + 2.3(3.5)(-15.3)
-9.03(-4.6) + 8.05(-15.3)
41.538 - 123.165
-81.627 <===
No because of it is not an idiom
Answer:
(D) A stratified random sample
Step-by-step explanation:
A stratified random samples are samples that involves the use of stratified random sampling (or stratification) which involves the partition or division of a population into smaller subgroups (called strata). The division is done based on some shared characteristics and attributes. The case above is a stratified random sample because it involves the division of shoreline(population) into 100-foot plots(stratas or subgroups).