<span>The problem is to calculate the angles of the triangle. However, it is not clear which angle you have to calculate, so we are going to calculate all of them
</span>
we know that
Applying the law of cosines
c²=a²+b²-2*a*b*cos C------> cos C=[a²+b²-c²]/[2*a*b]
a=12.5
b=15
c=11
so
cos C=[a²+b²-c²]/[2*a*b]---> cos C=[12.5²+15²-11²]/[2*12.5*15]
cos C=0.694------------> C=arc cos (0.694)-----> C=46.05°-----> C=46.1°

applying the law of sines calculate angle B
15 sin B=11/sin 46.1-----> 15*sin 46.1=11*sin B----> sin B=15*sin 46.1/11
sin B=15*sin 46.1/11-----> sin B=0.9826----> B=arc sin (0.9826)
B=79.3°

calculate angle A
A+B+C=180------> A=180-B-C-----> A=180-79.3-46.1----> A=54.6°

the angles of the triangle are
A=54.6°
B=79.3°
C=46.1°

7 0

2 years ago

A researcher studying public opinion of proposed Social Security changes obtains a simple random sample of 35 adult Americans an

Liula [17]

Answer:

Adult required in the case of “a” 28 and in the case of “b” the adult requirement is 19.

Step-by-step explanation:

(a) The percentage of adult that support the change is 20 percent.

Now calculate the number of adult required.

Given p = 0.20

Use the below condition:

$np(1 – p) \geq 10 \\n \times 0.20 (1 – 0.20) = 10 \\n = 63 round off$

Since 35 adults are already there so required adults are 63 -35 = 28

(b) The percentage of adult that support the change is 25 percent.

Now calculate the number of adult required.

Given p = 0.25

Use the below condition:

$np(1 – p) \geq 10 \\n \times 0.25 (1 – 0.25) = 10 \\n = 54 (round off)$

Since 35 adults are already there so required adults are 54 -35 = 19 .

6 0

2 years ago