Answer:
And rounded up we have that n=99
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".
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 assume the value for
since we don't have previous info. And replacing into equation (b) the values from part a we got:
And rounded up we have that n=99
Since the question is asking how many pencils the teacher will have to give out, we can automatically ignore the 46 erasers from the problem because it is not relevant. The information was most likely put there to confuse you.
Each student is getting 28 pencils, so if we multiply the number of students by 28 pencils, we will find how many pencils the teacher will need to give out.
There are 42 children in the classroom, so multiply 42 by 28.
42 * 28 = 1,176
The teacher will have to give out <u>1,176 pencils</u> to her 42 children in the classroom.
Answer:
m - 18
Step-by-step explanation:
Symbolically, that difference would be written as m - 18.
Answer:
3.375 miles
Step-by-step explanation:
Each day Maria walks 0.75 miles, so if she walks for 4.5 days, then 0.75*4.5= 3.375 miles.