Answer:
About 99.7% of births would be expected to occur within 51 days of the mean pregnancy length
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Standard deviation = 17.
About what percentage of births would be expected to occur within 51 days of the mean pregnancy length?
51/17 = 3.
So, within 3 standard deviations of the mean.
About 99.7% of births would be expected to occur within 51 days of the mean pregnancy length
Let's analyse each option:
A.
Spending money means the money will decrease, so it would be represented by minus 32.
B.
Dropping a rock means its height will decrease, so minus 32 would fit better.
C.
The speed is decreasing, so minus 32 as well.
D.
The amount of books is increasing, so positive 32 fits better in this situation.
Therefore the correct option is D.
The greatest common factor of 28 and 72<span>, is </span><span>4</span>
Answer:
24; 118; 102
Step-by-step explanation:
Starting from A: there are two ways. One, is a theorem that says "the amplitude of the external angle of a triangle is equal to the sum of the amplitudes of the two angles not sharing the vertex". Which translates to the equation 
which has solution 
.
Problem B is a red herring: x and 118° are corresponding angles related to the two parallel lines with a transversal, and they have the same amplitude, thus 
Finally, letter C : you know the sum of the internal angles of a triangle is 180°. It means that 
or, with simple calculations (subtract 41 and 37 from both sides) 
