Answer:
12
Step-by-step explanation:
To find the mean, we add up all the numbers and divide by the number of numbers
(19+ 12+9+ 6+ 12+ 8+ 18+ 12+ 14+ 10)/10
120/10
12
Answer:
Hence, option: B is correct (11.02 seconds)
Step-by-step explanation:
Spencer hits a tennis ball past his opponent. The height of the tennis ball, in feet, is modeled by the equation h(t) = –0.075t2 + 0.6t + 2.5, where t is the time since the tennis ball was hit, measured in seconds.
Now we are asked:
How long does it take for the ball to reach the ground?
i.e. we have to find the value of t such that height is zero i.e. h(t)=0.

or 
i.e. we need to find the roots of the above quadratic equation.
on solving the equation we get two roots as:
t≈ -3.02377 and t≈11.0238
As time can't be negative; hence we will consider the value of t as t≈11.0238.
Hence it takes 11.02 seconds for the ball to reach the ground.
Hence option B is correct (11.02 seconds).
If we represent Tobin's speed as x, we can write her opponent's speed as
x-2 (since Tobin is 2 more than them). In addition, since it's in miles per hour, and 45 minutes is 3/4 of an hour, we can say that 3/4ths of her speed in miles per hour is how long the race is, so (3/4)(x-2)=distance of race. In addition, since it only took Tobin 30 minutes, and 30 minutes is half an hour, x/2 (half of her miles per hour) is the length of the race, so (3/4)(x-2)=(1/2)x. Expanding it, we get 3x/4-6/4=x/2. Subtracting x/2 (or 2x/4) from both sides, we get x/4-6/4=0 and by adding 6/4 to both sides we get x/4=6/4. Multiplying 4 to both sides, we get that x=6=Tobin's speed in miles per hour
Answer:
75 less student tickets than adult tickets. The total is 625 tickets. So the student and adult tickets have to equal 625 when added.
Step-by-step explanation:
Student tickets: 275
Adult tickets: 350