Answer:
Step-by-step explanation:
We need to find the equation of parabola using given information
- Vertex: (0,0)
- Open to the left
- Focal width = 12
If parabola open left and passes through origin then equation is
Focal width = 12
Focal width passes through focus and focus is mid point of focal width.
Focus of above parabola would be (-a,0)
Passing point on parabola (-a,6) and (-a,-6)
Now we put passing point into equation and solve for a
a can't be negative.
Therefore, a=3
Focus: (-3,0)
Equation of parabola:
Please see the attachment of parabola.
90The information that you'd need in determining sample size when the standard deviation is unknown is:
z-value for the given level of confidence ⇒ The level of confidence is 90% and the z-value by convention is 1.645
The margin error (E) = 4%
The proportion of the population that you'd expect to vote for Yi. If this information isn't provided, use 50%. We call this value, p, the probability of success.
The probability of not success is q = 1 - 0.5 = 0.5
STEP 1:
Half the margin error = 0.04 ÷ 2 = 0.02
STEP 2:
Multiply the probability of success by the probability of fail = 0.5 × 0.5 = 0.25
STEP 3:
Divide z-score by half of E = 1.645 ÷ 0.02 = 82.25
Then square the answer = 82.25² = 6765 rounded to the nearest integer)
STEP 4:
Multiply the answer from STEP 2 by the answer from STEP 4
0.25 × 6765 = 1691 (rounded to the nearest integer)
Answer: Minimum Sample Size is 1691
Answer:
4 games
Step-by-step explanation:
<em>Robert called two bowling centers, Fannin Lanes and Fun Times Lanes, to déterminé the cost to bowl.</em>
Let x number of games played
y represents total cost to bowl
- Fannin Lanes charges 2.50 per games plus 2 for shoe rental
y = 2.50x + 2
- Fun Time Lanes charges 2 per game plus 4 for shoe rental.
y = 2x + 4
<u><em>If total cost to bowl be same at both center</em></u>
2.50x + 2 = 2x + 4
2.5x - 2x = 4-2
0.5x = 2
x = 4
Hence, 4 games will the cost to bowl be the same at both center.
