If you are using a student's-t distribution for a homework problem below, you may assume that the underlying population is normally distributed. (In general, you must first prove that assumption, though.)
Among various ethnic groups, the standard deviation of heights is known to be approximately 3 inches. We wish to construct a 95% confidence interval for the mean height of male Swedes. 48 male Swedes are surveyed. The sample mean is 71 inches. The sample standard deviation is 2.8 inches.
$\overline{x}=$$\text{\_\_\_\_\_\_\_\_}$
$\sigma =$$\text{\_\_\_\_\_\_\_\_}$
${s}_{x}=$$\text{\_\_\_\_\_\_\_\_}$
$n=$$\text{\_\_\_\_\_\_\_\_}$
$n-1=$$\text{\_\_\_\_\_\_\_\_}$
Define the Random Variables
$X$ and
$\overline{X}$ , in words.
Which distribution should you use for this problem? Explain your choice.
Construct a 95% confidence interval for the population mean height of male Swedes.
State the confidence interval.
Sketch the graph.
Calculate the error bound.
What will happen to the level of confidence obtained if 1000 male Swedes are surveyed instead of 48? Why?
71
3
2.8
48
47
$N$$(\text{71},\frac{3}{\sqrt{\text{48}}})$
CI: (70.15,71.85)
EB = 0.85
In six packages of “The Flintstones® Real Fruit Snacks” there were 5 Bam-Bam snack pieces. The total number of snack pieces in the six bags was 68. We wish to calculate a 96% confidence interval for the population proportion of Bam-Bam snack pieces.
Define the Random Variables
$X$ and
$P\text{'}$ , in words.
Which distribution should you use for this problem? Explain your choice
Calculate
$p\text{'}$ .
Construct a 96% confidence interval for the population proportion of Bam-Bam snack pieces per bag.
State the confidence interval.
Sketch the graph.
Calculate the error bound.
Do you think that six packages of fruit snacks yield enough data to give accurate results? Why or why not?
A random survey of enrollment at 35 community colleges across the United States yielded the following figures (source:
Microsoft Bookshelf ): 6414; 1550; 2109; 9350; 21828; 4300; 5944; 5722; 2825; 2044; 5481; 5200; 5853; 2750; 10012; 6357; 27000; 9414; 7681; 3200; 17500; 9200; 7380; 18314; 6557; 13713; 17768; 7493; 2771; 2861; 1263; 7285; 28165; 5080; 11622. Assume the underlying population is normal.
$\overline{x}=$
${s}_{x}=$$\text{\_\_\_\_\_\_\_\_}$
$n=$$\text{\_\_\_\_\_\_\_\_}$
$n-1=$$\text{\_\_\_\_\_\_\_\_}$
Define the Random Variables
$X$ and
$\overline{X}$ , in words.
Which distribution should you use for this problem? Explain your choice.
Construct a 95% confidence interval for the population mean enrollment at community colleges in the United States.
State the confidence interval.
Sketch the graph.
Calculate the error bound.
What will happen to the error bound and confidence interval if 500 community colleges were surveyed? Why?
8629
6944
35
34
${t}_{\text{34}}$
CI: (6244, 11,014)
EB = 2385
It will become smaller
From a stack of
IEEE Spectrum magazines, announcements for 84 upcoming engineering conferences were randomly picked. The mean length of the conferences was 3.94 days, with a standard deviation of 1.28 days. Assume the underlying population is normal.
Define the Random Variables
$X$ and
$\overline{X}$ , in words.
Which distribution should you use for this problem? Explain your choice.
Construct a 95% confidence interval for the population mean length of engineering conferences.
State the confidence interval.
Sketch the graph.
Calculate the error bound.
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?
Source:
OpenStax, Collaborative statistics homework book: custom version modified by r. bloom. OpenStax CNX. Dec 23, 2009 Download for free at http://legacy.cnx.org/content/col10619/1.2
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