Answer:
see below
Step-by-step explanation:
-2x + 9 < x − 9
Add 2x to each side
2x-2x + 9 < 2x+x − 9
9 < 3x-9
Add 9 to each side
9+9 < 3x
18 < 3x
Divide each side by 3
18/3 < 3x/3
6 < x
Open circle at 6 line going to the right
Answer:
-4(9d-1)
Step-by-step explanation:
(6d-10d×3+3d×2)-(5d×3+3d-4)
(6d-30d+6d)-(15d+3d-4)
6d-30d+6d-15d-3d+4d
-36d+4
-4(9d-1)
Answer:
131.2 ;
12.8 ;
(118.4, 144)
Step-by-step explanation:
Given :
X = 131.2, s=55 , and n= 50
Point estimate of the mean :
Since, sample size is large (n > 30) ; the sample mean = population mean according to the center limit theorem :
Margin of Error = Zcritical * s / sqrt(n)
Zcritical at 90% = 1.645
Margin of Error : 1.645 * (55 / sqrt(50))
Margin of Error : 1.645 * 7.7781745
Margin of Error = 12.795097
Margin of Error = 12.8
The confidence interval (C.I) :
C.I = x ± margin of error
C. I = 131.2 ± 12.8
(131.2 - 12.8) ; (131.2 + 12.8)
(118.4, 144)
Answer:
20
Step-by-step explanation:
Answer:
C. -0.34
Step-by-step explanation:
We have that for a normal distribution, the value of z can be calculated using the following formula:
z = (x - m) / sd
where x is the value to evaluate, m the mean and sd the standard deviation, we have those values x = 16.3, m = 17.4 and sd = 3.2
if we replace we have:
z = (16.3 - 17.4) /3.2
z = -0.3437
if we round to 2 decimal places, it would be -0.34, that is, the answer is C.
