z = -2.83
<u>Explanation:</u>
Given:
Mean, μ = 68
Standard deviation, σ = 6
Data point, x = 51
Z score, z = ?
We know:
Substituting the value we get:
A negative z score says that the data point is below average.
Hey there!
The answer to your question is Crew A
We can find this by first finding the unit rate, or acres per hour. We can divide the amount of acres by the amount of hours.
Crew A : 6/7.5 = 0.8 acres per hour
Crew B : 4.5/6 = 0.75 acres per hour
With the data above, we can see that Crew A is faster.
Hope it helps and have an amazing day! Remember, You've got this!
Answer:
We have to prove,
(A \ B) ∪ ( B \ A ) = (A U B) \ (B ∩ A).
Suppose,
x ∈ (A \ B) ∪ ( B \ A ), where x is an arbitrary,
⇒ x ∈ A \ B or x ∈ B \ A
⇒ x ∈ A and x ∉ B or x ∈ B and x ∉ A
⇒ x ∈ A or x ∈ B and x ∉ B and x ∉ A
⇒ x ∈ A ∪ B and x ∉ B ∩ A
⇒ x ∈ ( A ∪ B ) \ ( B ∩ A )
Conversely,
Suppose,
y ∈ ( A ∪ B ) \ ( B ∩ A ), where, y is an arbitrary.
⇒ y ∈ A ∪ B and x ∉ B ∩ A
⇒ y ∈ A or y ∈ B and y ∉ B or y ∉ A
⇒ y ∈ A and y ∉ B or y ∈ B and y ∉ A
⇒ y ∈ A \ B or y ∈ B \ A
⇒ y ∈ ( A \ B ) ∪ ( B \ A )
Hence, proved......
