Answer:
And we can find this probability using the complement rule and the normal standard distribution 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 number of attacks of a population, and for this case we know the distribution for X is given by:
Where
and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the complement rule and the normal standard distribution and we got:
It’s easy pi is equal to 3.14 so your answer is c
Answer: A
Step-by-step explanation:
<span>So we want to know how much clay did Joseph add after he built the cone. So the formula for the volume of the cone is V=(1/3)*pi*r^2*h where r is the radius and h is height. We know h1=12cm and r1=6cm, r2=6cm and h2=18 cm. So to get the amount of added clay Va we simply subtract the volume of the clay of the first cone V1 from the volume of the second cone V2: Vd=V2-V1=(1/3)*pi*(r1^2)*h1 - (1/3)+pi*(r2^2)*h2. Va=678.24 cm^3-452.39 cm^3= 266.08 cm^3.</span>