Triangles have 3 vertices. The total is 21 vertices. 21 / 3 = 7. He drew 7 triangles.
Answer:
Times 10 magnify
Step-by-step explanation:
The answer is c
Ok please thanks me if I’m correct
If is not correct comment
Answer:
a) A. The population must be normally distributed
b) P(X < 68.2) = 0.7967
c) P(X ≥ 65.6) = 0.3745
Step-by-step explanation:
a) The population is normally distributed having a mean (
) = 64 and a standard deviation (
) = ![\frac{19}{\sqrt{14} }](https://tex.z-dn.net/?f=%5Cfrac%7B19%7D%7B%5Csqrt%7B14%7D%20%7D)
b) P(X < 68.2)
First me need to calculate the z score (z). This is given by the equation:
but μ=64 and σ=19 and n=14,
and ![\sigma_x=\frac{ \sigma}{\sqrt{n} }=\frac{19}{\sqrt{14} }](https://tex.z-dn.net/?f=%5Csigma_x%3D%5Cfrac%7B%20%5Csigma%7D%7B%5Csqrt%7Bn%7D%20%7D%3D%5Cfrac%7B19%7D%7B%5Csqrt%7B14%7D%20%7D)
Therefore: ![z=\frac{68.2-64}{\frac{19}{\sqrt{14} } }=0.83](https://tex.z-dn.net/?f=z%3D%5Cfrac%7B68.2-64%7D%7B%5Cfrac%7B19%7D%7B%5Csqrt%7B14%7D%20%7D%20%7D%3D0.83)
From z table, P(X < 68.2) = P(z < 0.83) = 0.7967
P(X < 68.2) = 0.7967
c) P(X ≥ 65.6)
First me need to calculate the z score (z). This is given by the equation:
Therefore: ![z=\frac{65.6-64}{\frac{19}{\sqrt{14} } }=0.32](https://tex.z-dn.net/?f=z%3D%5Cfrac%7B65.6-64%7D%7B%5Cfrac%7B19%7D%7B%5Csqrt%7B14%7D%20%7D%20%7D%3D0.32)
From z table, P(X ≥ 65.6) = P(z ≥ 0.32) = 1 - P(z < 0.32) = 1 - 0.6255 = 0.3745
P(X ≥ 65.6) = 0.3745
P(X < 68.2) = 0.7967