Test 3 Review

Test 3 Review

The procedure for using a normal distribution to approximate a _____ distribution includes a _________ correction

Continuity correction represents _______ whole number x by the interval ______

In 431 NFL Games that went into overtime 200 teams that won the coin toss won the game. Find the P( Atleast 200 wins)n =p =

Can we calculate question 3 with Binomial Probability formula? Why or why not?

What are the requirement checks for question #3? (Normal Distribution as approximate to the Binomial Distribution)

If the requirements for question 3 are met, then

µ = np and σ = square root of ( npq)

In 431 NFL Games that went into overtime 200 teams that won the coin toss won the game. Is the coin toss fair? What are the requirements of np

np≥ 5 and nq ≥ 5 where n is the total number of observations, p = success, and q= failure

If you find that np and nq are 5 or more then what does that mean?

µ = np and σ = npq explain

Find P(Exactly 200 wins)

What is a critical value? What is Za2? Question from pg 322

Find the Critical Value of Za2?

Confidence Level (CL) Alpha Critical Value Za290% .10 1.645

95% .05 1.96

99% .01 2.575

From pg 325

A Reuters poll of 1007 randomly selected adults show that 93% of them know twitter.

n= p=

Find the margin of Error, E, with 90% CLE = ( Za2) (Sqrt ( pq/n))

Find 90% CI estimate of the population proportion p: p-E < p < P+E

Based on the results above, can we conclude that more than 90% of adults know twitter

Questions 16 and 17 are related pg 328

Google hires you to find how many people buy tutoring services online. How many adults need to be surveyed for 99% CL that sample is no more than 4%

n= ((Za2) ^2 (p)(q)/ (E)^2 or n= ((Za2) ^2 (.25)/ (E)^2

Census reveals 65% use tutoring service onlinep=q= Za2 =

No prior data given. How do you find n?

pg 337

When estimating population mean with σ (sigma) not known. You follow two requirement


Pg 339

A sample of size n= 15 selected from normal distribution population find Critical Value ta2 corresponding to 99% CL.

Pg 341

Highway speeds of 60 50 85 70 80 40 80 construct a 99 CI, if the speed limit is 65 mph, df =n-1E= ta2 ( s/(sqrt(n)) s= 4.1

Pg 348

When do you choose t vs Z distribution?



Pg 253

How do you convert Nonstandard Normal Distribution to a standard Normal Distribution ?Z=(x-µ)/ σ)

There is a 71-inch-tall requirement to enter a club. If the sample mean is 60.3 and the standard deviation is 2.6 in. Find the percent of women who satisfy this requirement.

Because ___ is rarely known, the confidence interval estimates of ____ almost _____ use the t distribution instead of the normal distribution

σ, µ, always

t distribution properties:

As the sample size of n gets ______ the student t distribution gets closer to ______

Larger, normal distribution

Standard deviation varies with sample sizes, but is >1 (t- distribution), unlike the normal distribution Sigma = 1.