Answer:
The correct answer will be "0.756596 m²".
Step-by-step explanation:
The given values are:
The radius of an umbrella,
r = 0.4 m
The height of an umbrella,
h = 0.45 m
As we know,
The lateral surface of an umbrella will be:
⇒
On substituting the values, we get
⇒
⇒
So that the amount of fabric needed will be "0.756596 m²".
Answer:
If we divide both sides by we got:
And we can use the normal distribution table or excel to find the probabilites and we got:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the area of a population, and for this case we know the distribution for X is given by:
Where and
We select a a sample of n =4 and since the distribution for X is normal then we know that the distribution for the sample mean is given by:
And we want to find this probability:
If we divide both sides by we got:
And we can use the normal distribution table or excel to find the probabilites and we got: