Answer:
a) 81.5%
b) 95%
c) 75%
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 266 days
Standard Deviation, σ = 15 days
We are given that the distribution of length of human pregnancies is a bell shaped distribution that is a normal distribution.
Formula:

a) P(between 236 and 281 days)

b) a) P(last between 236 and 296)

c) If the data is not normally distributed.
Then, according to Chebyshev's theorem, at least
data lies within k standard deviation of mean.
For k = 2

Atleast 75% of data lies within two standard deviation for a non normal data.
Thus, atleast 75% of pregnancies last between 236 and 296 days approximately.
Answer: 205 lbs
here are all the answers http://washburn.mpls.k12.mn.us/uploads/normal_calculations_practice_key.pdf
Step-by-step explanation:
If the axis of symmetry is x=-1, the vertex will have x-coordinate -1.
The point (0, 5) cannot be the vertex. The friend is not correct.
_____
If the point (1, 5) is on the graph so is the image of that point when it is reflected across the axis of symmetry. That image point is (-3, 5). A parabola that goes through points (1, 5) and (-3, 5) will not go through point (0, 5).
Answer:
25
Step-by-step explanation: