Answer:
0.6247
Step-by-step explanation:
The formula for calculating a Z-score is Z = (X - μ)/σ,
where x is the raw score
μ is the population mean
σ is the population standard deviation.
From the question,
μ = 51, σ = 10. We are to find P(36 ≤ X ≤ 56)
Step 1
Find the Probability of X ≤ 36
μ = 51, σ = 10
Z = (X - μ)/σ
Z = 36 - 51/ 10
Z = -15/10
Z = -1.5
We find the Probability of Z = -1.5 from Z-Table
P(X <36) = P(X = 36) = P(Z = -1.5)
= 0.066807
Step 2
Find the Probability of X ≤ 56
μ = 51, σ = 10
Z = (X - μ)/σ
Z = 56 - 51/ 10
Z = 5/10
Z = 0.5
We find the Probability of Z = 0.5 from Z-Table:
P(X < 56) = P(X = 56) = P(Z = 0.5)= 0.69146
Step 3
Find P(36 ≤ X ≤ 56)
P(36 ≤ X ≤ 56) = P(X ≤ 56) - P(X ≤ 36)
= P( Z = 0.5) - P(Z = -1.5)
= 0.69146 - 0.066807
= 0.624653
Approximately to 4 decimal places , P(36 ≤ X ≤ 56) = 0.6247
Answer: the expected population of the city in 30 years is 5470781
Step-by-step explanation:
The population growth is exponential. The growth rate is exponential. We would apply the formula for exponential growth which is expressed as
A = P(1 + r)^t
Where
A represents the population after t years.
t represents the number of years.
P represents the initial population.
r represents rate of growth.
From the information given,
P = 3.5 × 10^6
r = 1.5% = 1.5/100 = 0.015
t = 30 years
Therefore,
A = 3.5 × 10^6(1 + 0.015)^30
A = 3.5 × 10^6(1.015)^30
A = 5470781
Answer:

Step-by-step explanation:
The given equation is 
Group similar terms to get:


Square both sides to obtain:


Add 6 to both sides

Simplify the right hand side to obtain;

You can write it
7 to 8
7:8