The student will calculate confidence intervals for means when the population standard deviation is known.

Given

The mean age for all Foothill College students for a recent Fall term was 33.2. The population standard deviation has been pretty consistent at 15. Suppose that twenty-five Winter students were randomly selected. The mean age for the sample was 30.4. We are interested in the true mean age for Winter Foothill College students.
(
(External Link)

Let
$X=$ the age of a Winter Foothill College student

Calculating the confidence interval

$\overline{x}=$

30.4

$n$ =

25

15=(insert symbol here)

$\sigma $

Define the Random Variable,
$\overline{X}$ , in words.

$\overline{X}$ =

the mean age of 25 randomly selected Winter Foothill students

What is
$\overline{x}$ estimating?

$\mu $

Is
${\sigma}_{x}$ known?

yes

As a result of your answer to (4), state the exact distribution to use when calculating the Confidence Interval.

Normal

Explaining the confidence interval

Construct a 95% Confidence Interval for the true mean age of Winter Foothill College students.

How much area is in both tails (combined)?
$\alpha =$$\text{\_\_\_\_\_\_\_\_}$

0.05

How much area is in each tail?
$\frac{\alpha}{2}=$$\text{\_\_\_\_\_\_\_\_}$

In one complete sentence, explain what the interval means.

Discussion questions

Using the same mean, standard deviation and level of confidence, suppose that
$n$ were 69 instead of 25. Would the error bound become larger or smaller? How do you know?

Using the same mean, standard deviation and sample size, how would the error bound change if the confidence level were reduced to 90%? Why?

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?

fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.

Tarell

what is the actual application of fullerenes nowadays?

Damian

That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.

Tarell

what is the Synthesis, properties,and applications of carbon nano chemistry

Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.

Harper

Do you know which machine is used to that process?