It is given that the circumference of the circle is 19.5 inches. Let the diameter is d inches .
And the formula of circumference is
Substituting the value of C, we will get
When the diameter increased by 3, then the circumference is
And the circumference , when diameter is increased by 3 is 29 inches .
Answer:
Let X the random variable that represent the heights of a population, and for this case we know the distribution for X is given by:
Where and
Since the distribution for X is normal then the we know that the distribution for the sample mean is given by:
And the standard error is given by:
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 heights of a population, and for this case we know the distribution for X is given by:
Where and
Since the distribution for X is normal then the we know that the distribution for the sample mean is given by:
And the standard error is given by: