Answer:
<u>Hours in first month = 8</u>
Step-by-step explanation:
AS it is given
He volunteered fr the first month = x hours
He volunteered for the second month = 12/3 times of first month
which will be = 12/3 * x
Total Hours volunteered = 40 hours
Now according to the given conditions
Volunteered first month + volunteered second month = total
putting this gives
x + 12/3 8 x = 40
as 12/3 = 4 so
it becomes
x + 4x = 40
solcing it will gives
5x = 40
x = 40/5
x = 8
<u><em>So Numbers of hours worked in first month are 8</em></u>
<u><em></em></u>
<u>I hope this help you! :)</u>
we know that
In an Arithmetic Sequence the difference between one term and the next is a constant
This problem is an Arithmetic Sequence
where
the first term is 
and
the common difference is 
In general we can write an Arithmetic Sequence as a rule

where
a1 is the first term
d is the common difference
so

<u>Find the term a7</u>
![an=a1+d*(n-1)\\ \\ a7=23+(-2)*[7-1]\\ \\\\ a7=23-12\\ \\\\ a7=11](https://tex.z-dn.net/?f=%20an%3Da1%2Bd%2A%28n-1%29%5C%5C%20%5C%5C%20%20a7%3D23%2B%28-2%29%2A%5B7-1%5D%5C%5C%20%5C%5C%5C%5C%20a7%3D23-12%5C%5C%20%5C%5C%5C%5C%20%20%20%20a7%3D11%20%20%20%20%20)
therefore
<u>the answer is</u>

Answer:
Step-by-step explanation:
a) Sample statistics are used to estimate population value. Since 48% is a sample proportion, therefore, it is a sample statistic.
b) For 95% confidence level, z* = 1.96.
\hat{p}\pm z^* \sqrt{\frac{\hat{p}(1-\hat{p})}{n}}= 0.61\pm 0.61\sqrt{\frac{0.61(1-0.61)}{1578}}=0.61\pm 0.024 \ or (0.586, 0.634).
We are 95% confident that the true proportion of US residents who think marijuana should be made legal lies between 58.6% and 63.4%.
c)
\\np=1578(0.61)=962.58
\\n(1-p)=1578(1-0.61)=615.42
Since both np and n(1-p), are at least 10, the normal model is a good approximation for these data.
d) As the lower limit of confidence interval is less than 0.5, less than 50% population is also a plausible value of true proportion. This means the statement "Majority of Americans think marijuana should be legalized" is not justified.