Assume the random variable X is normally distributed with mean μ = 50 and standard deviation σ= 7. Compute the probability.
1 answer:
Complete question is;
Assume the random variable X is normally distributed with mean μ = 50 and standard deviation σ = 7. What is the probability P (X > 42)?
Answer:
P(X > 42) = 0.1271
Step-by-step explanation:
We are given;
mean; μ = 50
Standard deviation; σ = 7
Formula for the z-score is;
z = (x - μ)/σ
Thus;
z = (42 - 50)/7
z = -1.14
Since we are looking for P (X > 42), then let's look up this z-value from the z-distribution table attached.
We have;
P(X > 42) = 0.1271
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Answer:
x = π/3, x = 5π/3, x = 4π/3
Step-by-step explanation:
Let's split the given equation (2cosx-1)(2sinx+√3 ) = 0 into two parts, and solve each separately. These parts would be 2cos(x) - 1 = 0, and 2sin(x) + √3 = 0.
Remember that the general solutions for cos(x) = 1/2 are x = π/3 + 2πn and x = 5π/3 + 2πn. In this case we are given the interval 0 ≤ x ≤2π, and therefore x = π/3, and x = 5π/3.
Similarly:
The general solutions for sin(x) = - √3/2 are x = 4π/3 + 2πn and x = 5π/3 + 2πn. Therefore x = 4π/3 and x = 5π/3 in this case.
So we have x = π/3, x = 5π/3, and x = 4π/3 as our solutions.