Answer:
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
We assume for this case a confidence level of 95%. 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 95% of confidence, our significance level would be given by
and
. And the critical value would be given by:

The confidence interval for the mean is given by the following formula:
The margin of error for the proportion interval is given by this formula:
(a)
And if we replace the values obtained we got this:
Answer:
19b-4
Step-by-step explanation:
7b+3(4b-2)+6÷3
Bracket comes first so we distribute 3 over the terms in the bracket
= 7b + 12b -6 +6 ÷ 3
First we solve division
= 7b + 12b -6 +6 ÷ 3
= 7b + 12b -6 +2
= (7b+12b)+(-6+2)
= 19b -4
This can't be simplified further as it can't be solved anymore
Answer:
9 hours.
Step-by-step explanation:
So, first, you have to determine what he makes per hour to make this as easy as possible. You need to first do 396 divided by 18, which gives you 22. He makes 22$ an hour. Next, now that you know what he makes, you can do 198 divided by 22, and that'll show how long he has to work to make that amount of money.
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In expanded form or decimal form 32/100 is equal to 0.32 or 32% or if simplified the fraction is 8/25
435 being the constant means that is what they started with
Hope this helps :)