You may notice that all of the terms have a common factor: . So, let's take the
out of all the terms. This gives us:
Using the Zero Product Property, we can say that both and
.
Let's solve both. is obvious, but we still need to solve our other term:
Our answer is x = -6, 0, 4.
Answer:
6.7% of children who finished the race in under 45 seconds.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 75 seconds
Standard Deviation, σ = 20 seconds
We are given that the distribution of time of completion is a bell shaped distribution that is a normal distribution.
Formula:
P(finished the race in under 45 seconds.)
P(x < 45)
Calculation the value from standard normal z table, we have,
6.7% of children who finished the race in under 45 seconds.