It's quite simple when you break it down
20/45 let's divide by 5
4/9
we can't divide anymore, no common denominator. The answer is 4/9
Total tickets sold :
14 + 6 = 20
fraction of child tickets sold = 14/20
then, we convert this fraction to %.
14/20 = 70/100
( multiply by 5 )
percentage = 70%
Looks like a badly encoded/decoded symbol. It's supposed to be a minus sign, so you're asked to find the expectation of 2<em>X </em>² - <em>Y</em>.
If you don't know how <em>X</em> or <em>Y</em> are distributed, but you know E[<em>X</em> ²] and E[<em>Y</em>], then it's as simple as distributing the expectation over the sum:
E[2<em>X </em>² - <em>Y</em>] = 2 E[<em>X </em>²] - E[<em>Y</em>]
Or, if you're given the expectation and variance of <em>X</em>, you have
Var[<em>X</em>] = E[<em>X</em> ²] - E[<em>X</em>]²
→ E[2<em>X </em>² - <em>Y</em>] = 2 (Var[<em>X</em>] + E[<em>X</em>]²) - E[<em>Y</em>]
Otherwise, you may be given the density function, or joint density, in which case you can determine the expectations by computing an integral or sum.
Answer:
A. 30
Step-by-step explanation:
The interquartile range for a box and whiskers plot, is the value from the right side of the box minus the value of the left side of the box.
In this case at the far right side of the box it is at 130, at the far left side of the box it is at 100.
130-100=30