Before 1918, approximately 60% of the wolves in a region were male, and 40% were female. however, cattle ranchers in this area have made a determined effort to exterminate wolves. from 1918 to the present, approximately 70% of wolves in the region are male, and 30% are female. biologists suspect that male wolves are more likely than females to return to an area where the population has been greatly reduced. (round your answers to three decimal places.) (a) before 1918, in a random sample of 12 wolves spotted in the region, what is the probability that 9 or more were male? what is the probability that 9 or more were female? what is the probability that fewer than 6 were female? (b) for the period from 1918 to the present, in a random sample of 12 wolves spotted in the region, what is the probability that 9 or more were male? what is the probability that 9 or more were female? what is the probability that fewer than 6 were female?

A) 0.2253, 0.0153; B) 0.4925, 0.0017

Step-by-step explanation:

This is a binomial distribution.  This is because there are only two outcomes; each trial is independent of each other; and the outcomes are independent.

This means we use the formula

For part A,

There are 12 wolves selected; this means n = 12.  We want the probability that 9 or more are male; this makes r = 9, 10, 11 or 12.  We will find each probability and add them together.

p, the probability of success, is 0.6 for the first question (males).  This makes 1-p = 1-0.6 = 0.4.  Together this gives us

We now want the probability that 9 or more are female; this makes r = 9, 10, 11 or 12.  p is now 0.4; this makes 1-p = 1-0.4 = 0.6.  This gives us

For part B,

There are again 12 wolves selected, so n = 12.  We want the probability in the first question that 9 or more are male; this makes r = 9, 10, 11 or 12.  The probability of success is now 0.7, so 1-p = 1-0.7 = 0.3

For the second question, the probability of success is now 0.3 and 1-p = 1-0.3 = 0.7:

80%

step-by-step explanation:

statement #3: proof- ang is congruent to ang ecd : angles are congruent.  

step-by-step explanation:

1: the missing angles in statement #3  

a.) acb  

reason- the reason why the answer is acb is because angle ecd and angle acb are both the same size *that's what the word congruent means this is really simple.  

2: the missing word in reason #3  

c.) vertical  

reason- the reason why the answer is vertical is because the angles in that diagram on figure 2 is slanted, which is vertical, and the e and a both lay on vertical lines. along with the other's, but e and a are the 2 main points you want to focus on. and c is kind of like your starting point, because c is for both angles, not just one.  

i hope that was and understanding.