Answer:
The 90% confidence interval for the population mean iron concentration is between 0.167 cc/m³ and 0.195 cc/m³.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find M as such

In which
is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 0.181 - 0.0140 = 0.167 cc/m³.
The upper end of the interval is the sample mean added to M. So it is 0.181 + 0.0140 = 0.195 cc/m³.
The 90% confidence interval for the population mean iron concentration is between 0.167 cc/m³ and 0.195 cc/m³.
<em>To convert decimal number 1</em><em>2</em><em>3</em><em> to quinary, follow these steps:</em>
<em>1</em><em>.</em><em> </em><em>Divide 1</em><em>2</em><em>3</em><em> </em><em>by 5 keeping notice of the quotient and the remainder.</em>
<em>2</em><em>.</em><em>Continue dividing the quotient by 5 until you get a quotient of zero.</em>
<em>3</em><em>.</em><em> </em><em>Then just write out the remainders in the reverse order to get quinary equivalent of decimal number 1</em><em>2</em><em>3</em><em>.</em>
I. H o p e It. R I g h t.
(x - 9) (x-3)
Answer:
b²+3.5a+8.4b
Step-by-step explanation:
Given the expression
3b^2 + 2(a+5.4b) -2.4b + 1.5a - 2b^2
Expand
3b^2 + 2a+10.8b -2.4b + 1.5a - 2b^2
Collect the like terms
= 3b²-2b²+2a+1.5a+10.8b-2.4b
= b²+3.5a+8.4b
Hence the equivalent expression is b²+3.5a+8.4b