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This module is the complementary teacher's guide for the Central Limit Theorem chapter of the Collaborative Statistics collection (col10522) by Barbara Illowsky and Susan Dean.

The Central Limit Theorem (CLT) is considered to be one of the most powerful theorems in all of statistics and probability. It states that if you draw samples of size n and average (or sum) them, you will get a distribution of averages (or sums) that follow a normal distribution.

Suppose μ and σ are the original mean and standard deviation of the population from which each sample of size n is drawn. Let X - = the random variable for the average of n samples. Let x = the random variable for the number of n samples

X ~ N ( μ , σ n )

Σ x ~ N ( n μ , n σ )

The dice experiment

At the beginning of the chapter, there is a dice experiment. Together with the students, do the experiment. The example consists of rolling 10 times each, 1 die, 2 dice, 5 dice, and 10 dice and averaging the faces. Draw graphs (histograms are OK). This experiment, most of the time, shows that, as the number of dice increase, the graph looks more and more bell-shaped. Because the samples taken are usually small, you will not necessarily get a perfect bell-shaped curve. However, the students should get the idea.

Calculate averages

It can be shown that the average amount of money one person spends on one trip to a particular supermarket is $51. The averages follow an exponential distribution.

Find the probability that the average of 40 samples is more than $60.

Let X - = the average amount of money that 40 people spend. Have the students draw the appropriate picture, labeling the x-axis with X - . The mean μ = 51 and the standard deviation μ = 51 . If you are using the TI-83/84 series, use the function normalcdf(60, 10^99, 51, 51/40) .

The 75th percentile for the average amount spent by 40 people at the supermarket is $56.44. This means that 75% of the people spend no more than $56.44 and 25% spend no less than that amount.

This can be calculated by using the TI-83/84 function InvNorm(.75, 51, 51/ 40) .

Calculate sums

You can also do examples for sums. We, the authors, do not do sums because of time (we are on a quarter system). Help the students to find the probability that the total (sum) amount of money spent by 10 people at the supermarket is less than $500. Also, help them do a percentile problem.

Z-score formulas

If you want to teach the z-score formulas for averages and sums, they are:
  • z = value - μ ( - σ n )
  • z = value - n μ n σ

Assign practice

Assign the Practice in class to be done in groups.

Assign homework

Assign Homework . Suggested homework: (averages) 1a - f, 3, 5, 9, 10, 11a - d, f, k, 13a-c,g-j, 16, 17, 19 - 23

Questions & Answers

What are the factors that affect demand for a commodity
Florence Reply
differentiate between demand and supply giving examples
Lambiv Reply
differentiated between demand and supply using examples
Lambiv
what is labour ?
Lambiv
how will I do?
Venny Reply
how is the graph works?I don't fully understand
Rezat Reply
information
Eliyee
devaluation
Eliyee
t
WARKISA
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Lambiv
multiple choice question
Aster Reply
appreciation
Eliyee
explain perfect market
Lindiwe Reply
In economics, a perfect market refers to a theoretical construct where all participants have perfect information, goods are homogenous, there are no barriers to entry or exit, and prices are determined solely by supply and demand. It's an idealized model used for analysis,
Ezea
What is ceteris paribus?
Shukri Reply
other things being equal
AI-Robot
When MP₁ becomes negative, TP start to decline. Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 • Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of lab
Kelo
Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 • Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of labour (APL) and marginal product of labour (MPL)
Kelo
yes,thank you
Shukri
Can I ask you other question?
Shukri
what is monopoly mean?
Habtamu Reply
What is different between quantity demand and demand?
Shukri Reply
Quantity demanded refers to the specific amount of a good or service that consumers are willing and able to purchase at a give price and within a specific time period. Demand, on the other hand, is a broader concept that encompasses the entire relationship between price and quantity demanded
Ezea
ok
Shukri
how do you save a country economic situation when it's falling apart
Lilia Reply
what is the difference between economic growth and development
Fiker Reply
Economic growth as an increase in the production and consumption of goods and services within an economy.but Economic development as a broader concept that encompasses not only economic growth but also social & human well being.
Shukri
production function means
Jabir
What do you think is more important to focus on when considering inequality ?
Abdisa Reply
any question about economics?
Awais Reply
sir...I just want to ask one question... Define the term contract curve? if you are free please help me to find this answer 🙏
Asui
it is a curve that we get after connecting the pareto optimal combinations of two consumers after their mutually beneficial trade offs
Awais
thank you so much 👍 sir
Asui
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities, where neither p
Cornelius
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities,
Cornelius
Suppose a consumer consuming two commodities X and Y has The following utility function u=X0.4 Y0.6. If the price of the X and Y are 2 and 3 respectively and income Constraint is birr 50. A,Calculate quantities of x and y which maximize utility. B,Calculate value of Lagrange multiplier. C,Calculate quantities of X and Y consumed with a given price. D,alculate optimum level of output .
Feyisa Reply
Answer
Feyisa
c
Jabir
the market for lemon has 10 potential consumers, each having an individual demand curve p=101-10Qi, where p is price in dollar's per cup and Qi is the number of cups demanded per week by the i th consumer.Find the market demand curve using algebra. Draw an individual demand curve and the market dema
Gsbwnw Reply
suppose the production function is given by ( L, K)=L¼K¾.assuming capital is fixed find APL and MPL. consider the following short run production function:Q=6L²-0.4L³ a) find the value of L that maximizes output b)find the value of L that maximizes marginal product
Abdureman
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Source:  OpenStax, Collaborative statistics teacher's guide. OpenStax CNX. Oct 01, 2008 Download for free at http://cnx.org/content/col10547/1.5
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