Once you realize that 75% means 75/100, it is just a multiplication:
Answer:
169
Step-by-step explanation:

It is a rhombus, so u only need to square 13
Standard deviation= σ= 0.1
Confidence interval= 95%= 0.95
Significance level=α= 1-0.95= 0.05
α/2 = 0.025
At α/2 z( α/2 ) =1.960 [from statistic table]
Now,
the sample size at error of 0.02 is
0.02=z( α/2 )σ/√n
0.02=(1.960)*(0.1)/√n
5/49 = 1/√n
√n=49/5
n=96.04
n should be 96 or greater
Answer:180.3
Step-by-step explanation:
a=150
b=50
C=120
c^2=a^2+b^2-2 x a x b x cosC
c^2=150^2+50^2-2x150x50xcos120
c^2=150x150+50x50-2x150x50xcos120
c^2=22500+2500-15000cos120
c^2=25000-15000x-0.5
c^2=25000+7500
c^2=32500
c=√(32500)
c=180.3