The answer to the question is E. 2
Answer:
68.268%.
Step-by-step explanation:
Let \mu be the mean pregnancy length.
The given standard deviation,
days
The z-score:
z=\frac{x-\mu}{\sigma}
where x is any pregnancy length.
The range of x within 7 days of the mean pregnancy length is

z-score for this range is:


So, the area on the normally distributed curve for the above range of z-score will give the expected percentage of birds to occur within 7 days of the mean pregnancy length.
Now, from the z-score table:
The area from
to z=1 is 0.84134
and the area from
to z=-1 is 0.15866.
So, the area for -1<z<1
=0.84134 - 0.15866
=0.68268
Hence, the percentage of births would be expected to occur within 7 days of the mean pregnancy length=68.268%.
Answer:
Four sided figure with opposite sides that are parallel
Step-by-step explanation:
3 1/2 divided by 3= 1.1666
so 1/2 dozen muffins uses 1.1666 cups of flour.
1.1666 x 2= 2.3332
it takes 2.3332 cups of flour to make a dozen muffins
2.3332 = 2 1/3 cups of flour
2 1/3 cups of flour are needed for every dozen muffins made
B = c+8 --> c = b-8
a = b + 14
P = 63
a + b + c = 63
b+14 + b + b - 8 = 63
3b = 63 - 14 + 8
3b = 71 - 14
3b = 57
b = 57/3
b = 19
a = b+14
a = 19+14
a = 33
c = b-8
c = 19-8
c = 11