It is possible to calculate mathematically the area under the normal curve between any two values of z.
However, tables/software have been developed to give the areas under the normal curve to the left of particular values of z. The function is the probability of Z<z, or P(Z<z).
The area between two values z1 and z2 (where z2>z1) is therefore
P(Z<z2)-P(Z<z1).
For example, to find the area between z1=1.5, z2=2.5
is
P(Z<2.5)-P(Z<1.5)
=0.99379-0.93319
=0.06060
(above values obtained by software, such as R)
For example, the value P(Z<2.5) can be calculated using
P(Z<2.5)=erf(2.5/sqrt(2))/2+1/2
where erf(x) is a mathematical function that does not have an explicit formula (calculated by summation of series, or tabulated).
Answer:
I think the first x for question one is 0
Step-by-step explanation:
-2-(-1)/0-(-2)
Your first line calculation is already true but reversed. The demand will decrease (that mean the formula would be minus) by 20 gallons for every $0.4 price increase, which means 50 gallons/$. To find the formula you need to insert one sample of either the first equation (65gallon and $3.1) or 2nd equation (45 gallons and $3.5). The formula for demand should be:
q= C - 50p
65 gallon= C- 3.1 * 50
C= 65 gallon + 155 gallon= 220 gallon
The formula would be:
q= 220- 50p
So the second question can be solved by putting 0 on the Q. It would be:
q= 220- 50p
0=220-50p
50p=220
p= $4.4
Answer:
15 boys selected
Step-by-step explanation:
Given
--- The population
--- The sample selected
-- The proportion of boys
Required
The expected number of boys selected
The expected number is calculated by multiplying the sample size by the proportion of boys.
So, we have:
![Boys = p * n](https://tex.z-dn.net/?f=Boys%20%3D%20p%20%2A%20n)
![Boys = 0.152 * 100](https://tex.z-dn.net/?f=Boys%20%3D%200.152%20%2A%20100)
![Boys = 15.2](https://tex.z-dn.net/?f=Boys%20%3D%2015.2)
--- approximated
Answer: x is 3/5
Step-by-step explanation: your welcome