Sample size= n= 84
sample mean= x = 107 s
population standard deviation =σ= 11.7
As, population standard deviation is given so we use the estimate:
x(+/-) z(α/2)(σ/√n)
At 99% Confidence interval means significance level is α=1-0.99= 0.01
So,
α/2=0.005
Now, z at α/2=0.005
z= 2.576
Now, by putting values
107(+/-)((2.576)(11.7/√84))
( 107-((2.576)(11.7/√84)), 107+((2.576)(11.7/√84)) )
(103.7, 110.288)
3(x+4)=9
3x+12=9
3x=-3
x=-1
Hope this helps :D
#4 is 47, 48, 49
47+48+49=144
Answer:
53/5
Step-by-step explanation:
since 10 is the denominator of the denominator we can move it to the numerator, giving us 10n/5-3n = 1/5
multiply all sides by 5-3n, giving us 10n = (5-3n)/5
now multiply by 5 to get rid of the final denomintor, 50n = 5-3n
move 3n to the other side 53n = 5, n = 53/5