Question

1).In a test of a​ gender-selection technique, results consisted of 249

baby girls and 19 baby boys. Based on this​ result, what is the probability of a girl born to a couple using this​ technique? Does it appear that the technique is effective in increasing the likelihood that a baby will be a​ girl?

The probability that a girl will be born using this technique is approximately ?  ​(Type an integer or decimal rounded to three decimal places as​ needed.)

2.)In a genetics experiment on​ peas, one sample of offspring contained 368 green peas and

14 yellow peas. Based on those​ results, estimate the probability of getting an offspring pea that is green. Is the result reasonably close to the value of 3/4

that was​ expected? The probability of getting a green pea is approximately ?  ​(Type an integer or decimal rounded to three decimal places as​ needed.)

3.)Use the following results from a test for marijuana​ use, which is provided by a certain drug testing company. Among

149 subjects with positive test​ results, there are 28 false positive​ results; among 157 negative​ results, there are

3 false negative results. If one of the test subjects is randomly​ selected, find the probability that the subject tested negative or did not use marijuana.​ (Hint: Construct a​ table.)

The probability that a randomly selected subject tested negative or did not use marijuana is ? ​(Do not round until the final answer. Then round to three decimal places as​ needed.)

Answer 1

1)

probability of a girl born to a couple using this​ technique =249/(249+19)=0.9291 ~0.929

2)

probability of getting an offspring pea that is green =368/(368+14)=0.963

3)

	positive	negative	total
use	121	3	124
do not use	28	154	182
total	149	157	306

probability that a randomly selected subject tested negative or did not use marijuana is

=(157+182-154)/306=0.605