Answer:
The random variable (number of toppings ordered on a large pizza) has a mean of 1.14 and a standard deviation of 1.04.
Step-by-step explanation:
<em>The question is incomplete:</em>
<em>The probability distribution is:</em>
<em>x P(x) </em>
<em> 0 0.30 </em>
<em>1 0.40 </em>
<em>2 0.20 </em>
<em>3 0.06 </em>
<em>4 0.04</em>
The mean can be calculated as:
(pi is the probability of each class, Xi is the number of topping in each class)
The standard deviation is calculated as:
Answer:
y = - (x - 1)² + 2
Step-by-step explanation:
Any point (x, y) on the parabola is equidistant from the focus and the directrix.
Using the distance formula
= | y - 6 |
Square both sides
(x - 1)² + (y + 2)² = (y - 6)² ( expand the factors in y )
(x - 1)² + y² + 4y + 4 = y² - 12y + 36 ( subtract y² - 12y from both sides )
(x - 1)² + 16y + 4 = 36 ( subtract 4 from both sides )
(x - 1)² + 16y = 32 ← subtract (x - 1)² from both sides )
16y = - (x - 1)² + 32 ( divide all terms by 16 )
y = - (x - 1)² + 2