Answer:
C
Step-by-step explanation:
Given
tanθ = =
This is a right triangle with legs 1 and 2
Using Pythagoras' identity
hypotenuse² = 1² + 2² = 1 + 4 = 5 ( take square root of both sides )
hypotenuse =
θ is in the 3rd quadrant where sinθ < 0 , then
sinθ = = -
← rationalise the denominator
= - ×
= - → C
Answer:
And we can use the z scoe formula given by:
And if we find the z score for the limits we got:
And this probability is equivalent to:
Step-by-step explanation:
For this case we can define the random variable X as "number of miles between services" and we know the following info given:
The central limit theorem states that "if we have a population with mean μ and standard deviation σ and take sufficiently large random samples from the population with replacement, then the distribution of the sample means will be approximately normally distributed. This will hold true regardless of whether the source population is normal or skewed, provided the sample size is sufficiently large".
From the central limit theorem we know that the distribution for the sample mean is given by:
We select a random sample size of n =44. And we want to find this probability:
And we can use the z scoe formula given by:
And if we find the z score for the limits we got:
And this probability is equivalent to: