Answer:
Standard error of mean = 689
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = $28,520
Standard Deviation, σ = $5600
Mean of sampling distribution =
As per Central Limit Theorem, if the sample size is large enough, then the sampling distribution of the sample means follow approximately a normal distribution.
Sample size, n = 66
Since the sample size is large, we can use normal distribution for approximation.
Standard error of mean =
Answer:
The probability that the maximum speed is at most 49 km/h is 0.8340.
Step-by-step explanation:
Let the random variable<em> </em><em>X</em> be defined as the maximum speed of a moped.
The random variable <em>X</em> is Normally distributed with mean, <em>μ</em> = 46.8 km/h and standard deviation, <em>σ</em> = 1.75 km/h.
To compute the probability of a Normally distributed random variable we first need to convert the raw score of the random variable to a standardized or <em>z</em>-score.
The formula to convert <em>X</em> into <em>z</em>-score is:
Compute the probability that the maximum speed is at most 49 km/h as follows:
Apply continuity correction:
P (X ≤ 49) = P (X < 49 - 0.50)
= P (X < 48.50)
*Use a <em>z</em>-table for the probability.
Thus, the probability that the maximum speed is at most 49 km/h is 0.8340.