(7,0) is the distance between martina's guess and where the boat actually is
Answer:
475.
Step-by-step explanation:
We have been given that for a normal distribution with μ=500 and σ=100. We are asked to find the minimum score that is necessary to be in the top 60% of the distribution.
We will use z-score formula and normal distribution table to solve our given problem.

Top 60% means greater than 40%.
Let us find z-score corresponding to normal score to 40% or 0.40.
Using normal distribution table, we got a z-score of
.
Upon substituting our given values in z-score formula, we will get:





Therefore, the minimum score necessary to be in the top 60% of the distribution is 475.
1) Striangle = 1/2 * (12-8) * 4 = 1/2 * 4 * 4 = 8 km^2
2) Srectangle = 4 * 8 = 32 km^2
3) Sfigure = 8 + 32 = 40 km^2
Number C