<span>Answer:
Let P be the proportion of correct results of all polygraph results
H0: P ≥ 0.80
Ha: P < 0.80
Estimated p = 74 / 98 = 0.7551
Variance of proportion = p*(1-p)/n
= 0.8(0.2)/98 =0.0016327
S.D. of p is sqrt[0.001633] = 0.0404
z = ( 0.7551 - 0.8 ) / 0.0404 = -1.1112
P-value = P( z < -1.1112) = 0.1335
Since the p-value is greater than 0.05, we do not reject the null hypothesis. Based on the results there is no evidence that polygraph test results should be prohibited as evidence in trials.</span>
The value of cos 4x from the given identity is 0.999
<h3>Trigonometry identity</h3>
Given the cosine identity
cos8x = 13/36
Determine the value of x
8x = arccos(13/36)
8x = 0.36111
x = 0.36111/8
x = 0.04514
Determine the value of cos4x
cos4x = cos4(0.04514)
cos4(0.04514) = 0.999
Hence the value of cos 4x from the given identity is 0.999
Learn more trig identity here; brainly.com/question/7331447
Answer:

Step-by-step explanation:
ΔABC and ΔADB are similar (AAA).
Therefore the corresponging sides are in proportion:

Substitute:

<em>cross multiply</em>
