To develop this problem we will apply the concepts related to the Doppler effect. The frequency of sound perceive by observer changes from source emitting the sound. The frequency received by observer
is more than the frequency emitted by the source. The expression to find the frequency received by the person is,

= Frequency of the source
= Speed of sound
= Speed of source
The velocity of the ambulance is


Replacing at the expression to frequency of observer we have,


Therefore the frequency receive by observer is 878Hz
It will increase..........................
I am pretty sure the answer is C.
Based on the calculations, the average velocity is equal to 360 m/s and the percent difference is equal to 4.72%.
<h3>What is average velocity?</h3>
An average velocity can be defined as the total distance covered by a physical object divided by the total time taken.
<h3>What is an
average?</h3>
An average is also referred to as mean and it can be defined as a ratio of the sum of the total number in a data set to the frequency of the data set.
<h3>How to calculate the
average velocity?</h3>
Mathematically, the average velocity for this data set would be calculated by using this formula:
Average = [F(v)]/n
Vavg = [v₁ + v₂ + v₃ + v₄ + v₅)/5
Since the values of the average velocity from the table are missing, we would assume the following values for the purpose of an explanation:
Substituting the parameters into the formula, we have:
Vavg = [300 + 450 + 500 + 250 + 300)/5
Vavg = 1800/5
Vavg = 360 m/s.
Next, we would calculate the percent difference by using this formula:
![Percent \;difference = \frac{[V_{avg}\;-\;V_{sound}]}{V_{sound}} \times 100](https://tex.z-dn.net/?f=Percent%20%5C%3Bdifference%20%3D%20%5Cfrac%7B%5BV_%7Bavg%7D%5C%3B-%5C%3BV_%7Bsound%7D%5D%7D%7BV_%7Bsound%7D%7D%20%5Ctimes%20100)
Percent difference = [360 - 343]/360 × 100
Percent difference = 17/360 × 100
Percent difference = 0.0472 × 100
Percent difference = 4.72%.
Read more on average here: brainly.com/question/9550536
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