Answer:
1
Step-by-step explanation:
Given :
Mean, μ = 4
Standard deviation, s = 0.8
Sample size, n = 30
The distribution is independent.
Z = (x - μ) / s /sqrt(n)
Probability that downtime period is between 1 and 5
P(1≤ x ≤ 5) :
[(x - μ) / (s /sqrt(n))] ≤ Z ≤ [(x - μ) / (s /sqrt(n))]
[(1 - 4) / (0.8 /sqrt(30))] ≤ Z ≤ [(5 - 4) / (0.8 /sqrt(30)]
[-3 / 0.1460593] ≤ Z ≤] 1 / 0.1460593]
P(-20.539602 ≤ Z ≤ 6.8465342)
P(Z ≤ 6.8465342) - P(Z ≤ - 20.5396)
P(Z ≤ 6.8465342) = 1 (Z probability calculator)
P(Z ≤ - 20.5396) = 0 (Z probability calculator)
1 - 0 = 1
Answer: option 2. x²-1
Step-by-step explanation:
concept to know: a²-b²=(a+b)(a-b)
------------
(a+b)(a-b)=a²+b²
(x+1)(x-1)=x²-1
Hope this helps!! :)
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Answer:
A = 15 units²
Step-by-step explanation:
The figure has 1 pair of parallel sides and is therefore a trapezium.
The area (A) of a trapezium is calculated as
A = 
h (b₁ + b₂ )
where h is the perpendicular height between bases and b₁, b₂ are bases
here h = 3, b₁ = 3 , b₂ = 7 , then
A = × 3 × (3 + 7) = 1.5 × 10 = 15 units²
Answer:
x = 7
Step-by-step explanation:
Since the figures are similar then the ratios of corresponding sides are in proportion , that is
= 
, substitute values
= 
( cross- multiply )
48(7x - 9) = 60(4x + 4) ← divide both sides by 48
7x - 9 = 1.25(4x + 4) ← distribute parenthesis
7x - 9 = 5x + 5 ( subtract 5x from both sides )
2x - 9 = 5 ( add 9 to both sides )
2x = 14 ( divide both sides by 2 )
x = 7
Answer:
its b
Step-by-step explanation:
