3. B
Hope this helps ..........................
The answer is C, hope this helps!
Answer:
D) 14 seconds
Step-by-step explanation:
First we will plug 500 in for y:
500 = -4.9t² + 120t
We want to set this equal to 0 in order to solve it; to do this, subtract 500 from each side:
500-500 = -4.9t² + 120t - 500
0 = -4.9t²+120t-500
Our values for a, b and c are:
a = -4.9; b = 120; c = -500
We will use the quadratic formula to solve this. This will give us the two times that the object is at exactly 500 meters. The difference between these two times will tell us when the object is at or above 500 meters.
The quadratic formula is:

Using our values for a, b and c,

The two times the object is at exactly 500 meters above the ground are at 5 seconds and 19 seconds. This means the amount of time it is at or above 500 meters is
19-5 = 14 seconds.
Using the z-distribution, the p-value would be given as follows:
b) 0.0086.
<h3>What are the hypothesis tested?</h3>
At the null hypothesis we test if the means are equal, hence:

At the alternative hypothesis, it is tested if they are different, hence:

<h3>What are the mean and the standard error for the distribution of differences?</h3>
For each sample, they are given as follows:
Hence, for the distribution of differences, they are given by:
.
<h3>What is the test statistic?</h3>
The test statistic is given by:

In which
is the value tested at the null hypothesis.
Hence:


z = -2.63.
Using a z-distribution calculator, for a two-tailed test, with z = -2.63, the p-value is of 0.0086.
Hence option B is correct.
More can be learned about the z-distribution at brainly.com/question/13873630
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