Answer:
The ball will be 84 feet above the ground 1.125 seconds and 4.5 seconds after launch.
Step-by-step explanation:
Statement is incorrect. Correct form is presented below:
<em>The height </em>
<em> of an ball that is thrown straight upward from an initial position 3 feet off the ground with initial velocity of 90 feet per second is given by equation </em>
<em>, where </em>
<em> is time in seconds. After how many seconds will the ball be 84 feet above the ground. </em>
We equalize the kinematic formula to 84 feet and solve the resulting second-order polynomial by Quadratic Formula to determine the instants associated with such height:

(1)
By Quadratic Formula:

,
The ball will be 84 feet above the ground 1.125 seconds and 4.5 seconds after launch.
Answer:
Step-by-step explanation:
Given that that (X) the amount of time lapsed between consecutive trades on the New York Stock Exchange followed a normal distribution with a mean of 15 seconds.
i.e. X is normal with mean = 15 and unknown std deviation 
Given that
i.e. P(
z=-1.475 (from normal table)
Hence 
Using this we find P(X>17) = 
Answer:
109r6
Step-by-step explanationi got it
Answer:
the answer to this problem is D:(-2,4)(1,1)