Answer: 2.308 .
Step-by-step explanation:
Let X denotes the number of earthquakes in SanFernando valley region of Los Angeles in 1994.
Given: 
Probability is 0.87 that there will be at least 15 earthquakes .
i.e. 
![\Rightarrow\ P(\dfrac{X-\mu}{\sigma}\geq\dfrac{15-17.6}{\sigma})=0.87\\\\ \Rightarrow\ P(Z\geq\dfrac{-2.6}{\sigma})=0.87\ \ \ [Z=\dfrac{X-\mu}{\sigma}]](https://tex.z-dn.net/?f=%5CRightarrow%5C%20P%28%5Cdfrac%7BX-%5Cmu%7D%7B%5Csigma%7D%5Cgeq%5Cdfrac%7B15-17.6%7D%7B%5Csigma%7D%29%3D0.87%5C%5C%5C%5C%20%20%5CRightarrow%5C%20P%28Z%5Cgeq%5Cdfrac%7B-2.6%7D%7B%5Csigma%7D%29%3D0.87%5C%20%5C%20%5C%20%5BZ%3D%5Cdfrac%7BX-%5Cmu%7D%7B%5Csigma%7D%5D)
Z-value corresponding to p-value 0.87 is -1.1263 .
So, 
Hence, the required standard deviation = 2.308 .
Since the scatter plot has a line of best fit (the line you created), the points follow a linear pattern. Then looking at the slope, we see that it is positive (moves upward). The correlation is positive.
:)
Step-by-step explanation:
Each transversal crossing a line generates 2 pairs of vertical angles and for 3 transversal crossing the same line it will be 3 x2 = 6 pairs (or 12 angles)
