The diameters of bolts produced by a certain machine are normally distributed with a mean of 0.35 inches and a standard deviatio
1 answer:
Answer:
15.87%
Step-by-step explanation:
Notice that the mean of 0.35 inches with a standard deviation of 0.01 gives you when you add (to the right of the distribution), exactly 0.36. Since you want to find the probability (or percentage) of the bolts that have diameter LARGER than 0.36 in, that means you want to estimate the area under the Normal distribution curve from 0.36 to the right). See attached image.
We can use the tables of Z distribution for that, or the standard normal tables:
P(x>0.36) = P(z>(0.36-0.35)/0.01) = P(Z>1) = 0.1587 = 15.87%
You might be interested in
Answer:
To obtain a valid approximation for probabilities about the average daily downtime, either the underlying distribution(of the downtime per day for a computing facility) must be normal, or the sample size must be of 30 or more.
Step-by-step explanation:
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean and standard deviation
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
and standard deviation
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean and standard deviation
In this question:
To obtain a valid approximation for probabilities about the average daily downtime, either the underlying distribution(of the downtime per day for a computing facility) must be normal, or the sample size must be of 30 or more.