Step-by-step explanation:
17) 3x+5-12+4x+2x
3x+4x+2x +5-12
8x-7
if x =6
8*6-7 =48-7
= 41
18.) 9(3x-4y+8)
27x-36y+72
Answer:
a). 1/13
There are 4 5s. so 4/52
b). 3/13
12 total jack, king, and queen. 12/52
c). 15/26
30 cards are not face cards so 30/52
Well, luckily it is apparent that (x-1) is a root because when x=1 the equation is equal to zero. So we can divide the equation by that factor to find the other roots.
(2x^3+9x^2+4x-15)/(x-1)
2x^2 r 11x^2+4x-15
11x r 15x-15
15 r 0
(x-1)(2x^2+11x+15)=0
(x-1)(2x^2+6x+5x+15)=0
(x-1)(2x(x+3)+5(x+3))=0
(x-1)(2x+5)(x+3)=0
So the roots are x= -3, -2.5, 1
4x + 89.95 = 628.35 <== ur equation
4x = 628.35 - 89.95
4x = 538.40
x = 538.40 / 4
x = 134.60 <== the cost for each cavity filling
That is a very good question....
Look Grank
you know that:
confidence interval = mean +or- Margin of Error
and
Margin of Error = (z)*(standard deviation) / (sqrt of n)
where n is the number of sample records
So we need to calculate z-value firstly
It says: "<span>we want 90% confidence"
So that:
</span>
<span>confidence90% corresponds to z-value of 1.645
Plug that into our formula of </span><span>Margin of Error:
</span>Margin of Error = (1.645)*(22) / (sqrt of n)
"The sample mean is within 2.7 lb of the population mean" means that Margin of Error is 2.7
<span>Margin of Error:
</span>2.7 = (1.645)*(22) / (sqrt of n)
Now solve for n:
n=179.66~180
SO that 180<span> women must be randomly selected to estimate the mean weight of women in one age group.</span>
