Every confidence interval has associated z value. As confidence interval increases so do the z value associated with it.
The confidence interval can be calculated using following formula:
Where
is the mean value, z is the associated z value, s is the standard deviation and n is the number of samples.
We know that standard deviation is simply a square root of variance:
The confidence interval of 95% has associated z value of <span>1.960.
</span>Now we can calculate the confidence interval for our income:
Yes you have a good example.
x = number of cookies
2*x = total amount spent on cookies at $2 each
2x-3 = amount you pay after the $3 discount is applied one time for the entire order
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a more numeric example may be this
Lets say you bought 12 cookies, so x = 12
This means it costs 2*x = 2*12 = 24 dollars total if the discount doesnt apply
However, the 3 dollar discount is there, so the grand total is 24-3 = 21 dollars.
Definition of additive inverse.- If two numbers are added together and the sum is zero, they are the additive inverse of each other.
<span>......................................... IF A + B = 0 , they are the additive inverse of each other.
</span>
<span>Multiplicative Inverse.- If two numbers are multiplied together and the product is one. They are the multiplicative inverse of each other, also called reciprocal. </span>
<span>......................................... A.B = 1 , they are the multiplicative inverse of each other.
</span>
<span>Example of: </span>
<span>Additive inverses :................ 5 + ( - 5 ) = 0 </span>
<span>Multiplicative inverses...........5 x 1/5 = 1 </span>
