We can calculate (62 + 90) / 2 = 76. it's <span>known that 95% lies between the mean and twice the standard deviation. </span><span>if the mean is "μ" and the standard deviation is "σ": </span><span>μ-2σ and μ+2σ. i</span><span>f μ=76, then </span><span>76+2σ = 90, so 2σ = 14, so σ = 7.
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<span>the mean is 76 and the standard deviation 7. </span>
Square root of 100 = 10 cm. Next, 10*2 = 20^2 = 400 ft. Next, convert cm into ft, which would make 100 into about 3.3 ft. The ratio would then be about 3/400. Does that help?
Positive correlation.
Zero is x increases y stays the same
Negative is both decrease
I think the answer is C. 45 units
