Jess Todd
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study guide for statistics final exam

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Jess Todd
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Statistics final exam

Statistics final exam

Question 1 of 46

1

which of the following are binomial experiments or can be reduced to binomial experiments?

Select one or more of the following:

  • surveying 100 people to determine if they like sudsy soap

  • tossing a coin 100 times to see how many heads occur

  • drawing a card with replacement from a deck and getting a heart

  • asking 1000 people which brand of cigarettes

  • testing four different brands of aspirin to see which brands are effective

Explanation

Question 2 of 46

1

the expected value of a random variable can be thought of as a long-run average

Select one of the following:

  • True
  • False

Explanation

Question 3 of 46

1

the number of courses a student is taking this semester is an example of a continuous random variable

Select one of the following:

  • True
  • False

Explanation

Question 4 of 46

1

when the binomial distribution is used, the outcomes must be dependent

Select one of the following:

  • True
  • False

Explanation

Question 5 of 46

1

a binomial experiment has a fixed number of trials

Select one of the following:

  • True
  • False

Explanation

Question 6 of 46

1

what is the sum of the probabilities of all outcomes in a probability distribution

Select one of the following:

  • 0

  • 1/2

  • 1

  • it cannot be determined

Explanation

Question 7 of 46

1

how many outcomes are there in a binomial experiment

Select one of the following:

  • 0

  • 1

  • 2

  • it varies

Explanation

Question 8 of 46

1

the number of trials for a binomial experiment

Select one of the following:

  • can be infinite

  • is unchanged

  • is unlimited

  • must be fixed

Explanation

Question 9 of 46

1

the total area under a normal distribution is infinite

Select one of the following:

  • True
  • False

Explanation

Question 10 of 46

1

the standard normal distribution is a continuous distribution

Select one of the following:

  • True
  • False

Explanation

Question 11 of 46

1

all variables that are approximately normally distributed can be transformed to standard normal variables

Select one of the following:

  • True
  • False

Explanation

Question 12 of 46

1

the z value corresponding to a number below the mean is always negative

Select one of the following:

  • True
  • False

Explanation

Question 13 of 46

1

the area under the standard normal distribution to the left of z=0 is negative

Select one of the following:

  • True
  • False

Explanation

Question 14 of 46

1

the central limit theorem applies to means of samples selected from different populations

Select one of the following:

  • True
  • False

Explanation

Question 15 of 46

1

the mean of the standard normal distribution is

Select one of the following:

  • 0

  • 1

  • 100

  • variable

Explanation

Question 16 of 46

1

approximately what percentage of normally distributed data values will fall within 1 standard deviation above or below the mean?

Select one of the following:

  • 68%

  • 95%

  • 99.7%

  • variable

Explanation

Question 17 of 46

1

which is not a property of the standard normal distribution?

Select one of the following:

  • it's symmetric about the mean

  • it's uniform

  • it's bell shaped

  • its unimodal

Explanation

Question 18 of 46

1

when a distribution is positively skewed, the relationship of the mean, median, and mode from left to right will be?

Select one of the following:

  • mean, median, mode

  • mode, median, mean

  • median, mode, mean

  • mean, mode, median

Explanation

Question 19 of 46

1

the standard deviation of all possible sample means equals

Select one of the following:

  • the population standard deviation

  • the population standard deviation divided by the population mean

  • the population standard deviation divided by the square root of the sample size

  • the square root of the population standard deviation

Explanation

Question 20 of 46

1

Interval estimates are preferred over point estimates since the confidence level can be specified

Select one of the following:

  • True
  • False

Explanation

Question 21 of 46

1

for a specific confidence interval, the larger the sample size, the smaller the margin of error will be.

Select one of the following:

  • True
  • False

Explanation

Question 22 of 46

1

an estimator is consistent if as the sample size decreases, the value of the estimator approaches the value of the parameter estimated

Select one of the following:

  • True
  • False

Explanation

Question 23 of 46

1

to determine the sample size needed to estimate a parameter, you must know the margin of error

Select one of the following:

  • True
  • False

Explanation

Question 24 of 46

1

when a 99% confidence interval is calculated instead of a 95% confidence interval with n being the same, the margin of error will be

Select one of the following:

  • smaller

  • larger

  • the same

  • it cannot be determined

Explanation

Question 25 of 46

1

the best point of estimate of the population mean is

Select one of the following:

  • the sample mean

  • the sample median

  • the sample mode

  • the sample midrange

Explanation

Question 26 of 46

1

when the population standard deviation is unknown and the sample size is less than 30, what table value should be used in computing a confidence interval for a mean

Select one of the following:

  • z

  • t

  • chi-square

  • none of the above

Explanation

Question 27 of 46

1

No error is committed when the null hypothesis is rejected when it is false

Select one of the following:

  • True
  • False

Explanation

Question 28 of 46

1

when you are conducting the t test, the population must be approximately normally distributed

Select one of the following:

  • True
  • False

Explanation

Question 29 of 46

1

the test value separates the critical region from the noncritical region

Select one of the following:

  • True
  • False

Explanation

Question 30 of 46

1

the values of chi-square test cannot be negative

Select one of the following:

  • True
  • False

Explanation

Question 31 of 46

1

the chi-square test for variance is always one tailed

Select one of the following:

  • True
  • False

Explanation

Question 32 of 46

1

when the value of alpha is increased, the probability of committing a type 1 error is

Select one of the following:

  • decreased

  • increased

  • the same

  • none of the above

Explanation

Question 33 of 46

1

if you wish to test the claim that the mean of the population is 100, the appropriate null hypothesis is

Select one of the following:

  • x(bar) = 100

  • µ ≥ 100

  • µ ≤ 100

  • µ = 100

Explanation

Question 34 of 46

1

the degrees of freedom for the chi-square test for variances or standard deviation are

Select one of the following:

  • 1

  • n

  • n - 1

  • none of the above

Explanation

Question 35 of 46

1

for the t test, one uses ________ instead of σ

Select one of the following:

  • n

  • s

  • X²

  • t

Explanation

Question 36 of 46

1

a negative relationship between two variables means that for the most part, as the x variable increases, the y variable decreases

Select one of the following:

  • True
  • False

Explanation

Question 37 of 46

1

a correlation coefficient of -1 implies a perfect linear relationship between the variables

Select one of the following:

  • True
  • False

Explanation

Question 38 of 46

1

even if the correlation coefficient is high (near +1) or low (near -1), it may not be significant

Select one of the following:

  • True
  • False

Explanation

Question 39 of 46

1

when the correlation coefficient is significant, you can assume x causes y

Select one of the following:

  • True
  • False

Explanation

Question 40 of 46

1

it is not possible to have a significant correlation by chance alone

Select one of the following:

  • True
  • False

Explanation

Question 41 of 46

1

in multiple regression, there are several dependent variables and one independent variable

Select one of the following:

  • True
  • False

Explanation

Question 42 of 46

1

the strength of the linear relationship between two quantitative variables is determined by the value of

Select one of the following:

  • r

  • a

  • x

  • s (subscript "est")

Explanation

Question 43 of 46

1

to test the significance of r, a(n) ____ test is used.

Select one of the following:

  • t

  • F

  • X²

  • none of the above

Explanation

Question 44 of 46

1

the test of significance for r has _______ degrees of freedom.

Select one of the following:

  • 1

  • n

  • n - 1

  • n - 2

Explanation

Question 45 of 46

1

the equation of the regression line used in statistics is

Select one of the following:

  • x = a + by

  • y = bx + a

  • y' = a +bx

  • x = ay + b

Explanation

Question 46 of 46

1

the coefficient of determination is

Select one of the following:

  • r

  • r²

  • a

  • b

Explanation

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