2. What type of sequence is this? 4,0-4,-8, -12,... Arthimetic Geometric Neither
1 answer:
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Answer:
d = 25
Step-by-step explanation:
The value of d has to satisfy the inequality
so replace d with one of the given options
We have to simplify the fraction first
It is given that the mean is 79.1 inches and standard deviation is 3.0 inches so it follows:
So the value from 75 to 81 is given by:
Use the table or a software to get the probability values and substitute to get the probability value as:
The probability is 0.6509.
Answer:
P [ 55 ≤ X ≤ 70 ] = 23.55 %
Step-by-step explanation:
We know:
μ₀ = mean of population σ = standard deviation
We begin for calculating the probability of X ≤ 55 so
Step 1:
μ₀ = 50 σ = 7
×₁ = ( μ - μ₀ ) ÷ σ ⇒ ×₁ = (55-50) ÷ 7 ⇒ ×₁ = 5 ÷ 7 ×₁ = 0.7143
We look z table and we have to interpolate
value (closest smaller Than ×₁ 0.71 and closest bigger than ×₁ 0.72
The associated area for these point are: 0.7611 and 0.7642
Taking diferences and by rule of three
0.01 ⇒ 0.0031
0.0042 ⇒ Δ Δ = 0.0013 and Area for ×₁ = 0.7624
That is the probability of X ≤ 55
Now we have to find the probability of X ≤ 70
We procede as in step 1
μ₀ = 50 σ = 7
×₂ = ( μ - μ₀ ) ÷ σ ⇒ ×₂ = (70-50) ÷ 7 ⇒ ×₂ = 20 ÷ 7 ×₂ = 2.8571
We look z table and we have to interpolate
for 2.85 ⇒ 0.9978 (area) 2.8571 - 2.85 = 0.007
for 2.86 ⇒ 0.9979 (area)
Therefore by rule of three we have
0.01 ⇒ 0.0001
0.007 ⇒ Δ Δ = 0.00007
And area for ×₂ = 2.8571 is equal to 0.99787 and the probability of
X ≤ 0.99787 or 99.79
Now if we look the annex drawing (the area we are looking for is enclose for the values x₁ and ×₂ (pink area) and is the diference between these two areas
So P [ 55 ≤ X ≤ 70 ] is 99.79 % - 76.24 % = 23.55
