Answer:
(22.74 ; 27.26)
Step-by-step explanation:
The confidence interval relation is stated as :
Mean ± Zcritical * σ/sqrt(n)
Mean = 25
σ = 6
The Zcritical at 95% = 1.96
Hence,
25 ± 1.96 * (6/sqrt(27))
25 ± 1.96 * 1.1547005
Lower boundary :
25 - (1.96 * 1.1547005) = 22.73678702
Upper boundary :
25 + (1.96 * 1.1547005) = 27.26321298
(22.74 ; 27.26)
Answer:
y>60
2*x+2*x<260
it's the only one that works
Step-by-step explanation:
Answer:
x - 15 = 22
Step-by-step explanation:
difference in math means subtraction
Answer:
(6, -4) does not fit with these two equations
Step-by-step explanation:
y = 8 - 2x
x + 3y = 12
fit (6, -4) into the equations
-4 = 8 - 2(6)
8 - 2(6) = 8 - 12 = -4
works for this one
6 + 3(-4) = 12
6 + 3(-4) = 6 - 12 = -6
doesnt work for this one
1) x + 3.2= -3.5
subtract 3.2 from both sides
x+ 3.2 - 3.2= -3.5 - 3.2
it cancels out on the left
x= -6.7
2) 8/9x= 32
divide both sides by 8/9
8/9x ÷ 8/9= 32 ÷ 8/9
it cancels out on the left
to divide on the right, multiply fraction by its reciprocal/inverse
x= 32 * 9/8
multiply numerators (top)
x= (32*9)/8
x= 288/8
x= 36
ANSWER: 1) x= -6.7; 2) x= 36
Hope this helps! :)
