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Organizing Data
Data Relationships
Normal Distributions
Probability & Distributions
Z-Scores/Sampling Distributions
100
This measure of center is more resistant to outliers than the mean.
What is the median?
100
observed y - predicted y
What is the residual?
100

What rule is described? If n>30, then the distribution is approximately normal.

What is the central limit theorem?

100
This type of random variable requires a fixed number of trials.
What is a binomial random variable?
100

A machine is used to put nails into boxes. It does so such that the actual number of nails in a box is normally distributed with a mean of 106 and standard deviation of 2. 

What percent of boxes contain more than 104 nails?


.8413

200
To calculate, subtract the mean of the distribution from the observed x, then divide by the standard deviation.
What is the z-score (or standardized value)?
200
Measures the direction and strength of a linear relationship between two quantitative variables.
What is correlation (or r)?
200

Taxes are normally distributed with mean fare $22.27 and standard deviation $2.20. 

Find the probability of a ride costing you between $21 and $24.

What is .5023 or 50.23%?

200
The type of variable where the probability distribution assigns probability as the area under the density curve above a specific interval.
What is a continuous random variable?
200

A machine is used to put nails into boxes. It does so such that the actual number of nails in a box is normally distributed with a mean of 106 and standard deviation of 2.

What is the z-score for a box containing 107 nails?

z= 0.5

300
This rule helps to determine if data is normally distributed by checking the number of observations within each interval.
What is the 68-95-99.7 rule?
300
The fraction of the variables in the values of y that is explained by the LSR of y on x.
What is the coefficient of determination (or r squared)?
300

State police believe that 70% of the drivers traveling on a major interstate highway exceed the speed limit. They set up a trap to get the speed of 80 cars.

What is the mean and standard deviation of the sampling distribution?

up=.70

sigmap=.0512

300
Events that have no outcomes in common and can never occur simultaneously, for which the addition rule is used.
What are disjoint events (or mutually exclusive events)?
300

A machine is used to put nails into boxes. It does so such that the actual number of nails in a box is normally distributed with a mean of 106 and standard deviation of 2.

How many nails represents the 28th percentile?

104.83, so 104

400
The square of the standard deviation.
What is the variance?
400
Applying a logarithmic transformation to both variables causes this type of model to become linear.
What is a power model?
400

State police believe that 70% of the drivers traveling on a major interstate highway exceed the speed limit. They set up a trap to get the speed of 80 cars.

What is the probability that the proportion of drivers who exceed the speed limit is less than 60%?

97.5%

400

Suppose a computer chip manufacturer rejects 2% of chips produced because they fail pre-sale testing.

What is the probability that the fifth chip you test is the first bad one you find?

.0184

400

The scores of students on the ACT college entrance exam has a normal distribution with mean 18.6 and standard deviation of 5.9.

We take a sample of 50 random students. What is the mean and standard deviation of the sample mean score of these 50 students?

mean= 18.6

Standard deviation= 2.630

500
This calculator command can be used to find the area under a normal distribution and above an interval.
What is normalcdf?
500
Write the equation of the LSRL in context using the minitab print out of weight of a car (in thousands of pounds) and fuel efficiency (in miles per gallon).

FE= -8.21362(weight)+48.7393

500

State police believe that 70% of the drivers traveling on a major interstate highway exceed the speed limit. They set up a trap to get the speed of 80 cars.

What sample proportion would be at the 95th percentile of this distribution?

78.4%
500

A pharmaceutical lab claims that a drug it produces causes serious side effects in 20 out of every 1000 people. To check this claim, a hospital administers the drug to 15 randomly selected patients and finds that 3 suffer serious side effects. If the lab’s claims are correct, what is the probability of the hospital obtaining the results it did?

.0028

500

The scores of students on the ACT college entrance exam has a normal distribution with mean 18.6 and standard deviation of 5.9.

What is the probability that the mean score of these students is 21 or higher?

.1545