Answer:
And rounded up we have that n=2663
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The population proportion have the following distribution
Solution to the problem
In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 99% of confidence, our significance level would be given by 
and 
. And the critical value would be given by:
The margin of error for the proportion interval is given by this formula:
(a)
And on this case we have that 
and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
We can assume an estimated proportion of 
since we don't have prior info provided. And replacing into equation (b) the values from part a we got:
And rounded up we have that n=2663
Answer:
Expected value for 4 tickets = $ -7.6
Step-by-step explanation:
Given - A lottery offers one $900 prize, one $600 Prize, three $400 prizes, and four $100 prizes. One thousand tickets are sold at $5 each.
To find - Find the expectation if a person buys four tickets. Assume that the player's ticket is replaced after each draw and that the same ticket can win more than one prize. Round to two decimal places for currency problems.
Proof -
Given that,
A lottery offers
one $ 900 prize
one $ 600 prize
three $ 400 prizes
Four $ 100 prizes
And
One thousand tickets are sold at $ 5 each
Now,
If the person bought 1000 tickets then the prize he gets is
= 900 + 600 + 3×400 + 4×100
= 900 + 600 + 1200 + 400
= $3100
And
The cost of 1000 tickets = 5×1000 = $ 5000
Now,
Price 1 ticket = 
= $ 3.1
⇒Expectation of 1 ticket = $ 3.1 - 5 = $ -1.9 (Here $5 is price of 1 ticket)
⇒Expected value for 4 tickets = $ 4× -1.9 = $ -7.6
⇒Expected value for 4 tickets = $ -7.6
They need to be like terms (so change the denominators into things that match)
<u>1 </u>x3 = <u>3</u>
4 x3 = 12
<u>1 </u>x4 = <u>4</u>
3 x4 = 12
4/12 + 3/12 = 7/12
So, 7/12 of the money was spent.
Answer:
x=291/76
Step-by-step explanation:
Convert:
1/2x(6x+ 1/2)=-0.8x+16-1.2
Remove parenthesis and move terms:
3x+1/4=-0.8x+14.8
Collect the like terms and convert:
3x+0.8x=14.8-1/4
Subtract the fractions:
3.8x=74/5-1/4
Divide both sides by 3.8:
3.8x=291/20
x=291/76
