10) A competency test has scores with a mean of 255 and a standard
1 answer:
Answer:
The percentage of scores higher than 72 is 99.85%
Explanation:
The empirical rule states that about 68% of observations falls within the first standard deviation (µ ± σ), 95% within the first two standard deviations (µ ± 2σ), and 99.7% within the first three standard deviations (µ ± 3σ)
We can use the relationship below
255-σ(61)=72
61σ=255-72
61σ=183
σ=3
The area is as shaded below
The percentage of scores higher than 72 is 99.7%+0.15%=99.85%
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Solution:
We are given:
Number of male fishes surveyed by Elena in a river = 350
Number of male fishes with eggs growing inside them = 150
Therefore the number of male fishes without eggs = 350 - 150 = 200
Now the ratio of male fish with egg cells to male fish without egg cells in the river is:
Therefore, the ratio of male fish with egg cells to male fish without egg cells in the river is