stats data bank-Which of the following is most likely a population as opposed to a sample?

1.

Which of the following is most likely a population as opposed to
a sample?

Answer

		respondents to a newspaper survey
		the first 5 students completing an assignment
		every third person to arrive at the bank
		registered voters in a county

4 points

Question 2

1.

Which of the following can be reduced by proper interviewer
training

Answer

		sampling error
		measurement error
		both of the above
		none of the above

4 points

Question 3

1.

According to the empirical rule, if the data form a
“bell-shaped” normal distribution, ________ percent of the
observation will be contained within 1 (one) standard deviation around the
arithmetic mean.

Answer

		68.26
		75.00
		88.89
		93.75

4 points

Question 4

1.

The probability that a new advertising campaign will increase
sales is asssessed as being 0.80. The probabliity that the cost of
devolping the new add campaign can be kept within the original budget
allocation is 0.40. Assuming that the two events are independent, the
probability that the cost is kept withing budget and the campain will increase
sales is:

Answer

		0.20
		0.32
		0.40
		0.88

4 points

Question 5

1.

In a non symmmetrical distribution:

Answer

		the range equals the interquartile range
		the interquartile range equals the mean
		the median does not equal the mean
		the variance equals the standard deviation

4 points

Question 6

1.

Which statement about the standard normal distribution is NOT
true

Answer

		It has a mean of 0
		It has a variance of 0
		has an area under the probability distribution curve equal to 1.
		has a standard deviation of 1.

4 points

Question 7

1.

If we know that the length of time it takes a college student to
find a parking spot in the library parking lot follows a normal distribution
with a mean of 4.5 minutes and a standard deviation of 3.2 minute, find the
probability that a randomly selected college student will find a parking spot
in the library parking lot in less than 4 minutes.

Answer

		0.4379
		0.5000
		0.5620
		0.9999

4 points

Question 8

1.

The following data represent the response (Y for yes and N for
no) from a sample of 40 college students to the question SDo you currently own
shares in any stocks? (8 points)N N Y N N N N Y N Y N N Y N Y Y N N N YN Y N N
N N Y N N N Y N N N Y N N Y N NWhat is the standard error of the sample
proportion of college students who own stocks?

Answer

		0.0114
		0.0724
		0.4582
		2.8982

4 points

Question 9

1.

If an economist wishes to determine whether there is evidence
that average family income in a community exceeds $25,000

Answer

		either a one-tailed or two-tailed test could be used with equivalint results.
		a one tailed test should be utilized.
		a two-tailed test shoud be utilized.
		none of the above.

4 points

Question 10

1.

The power of a
statistical test is

Answer

		the probability of not rejecting Ho when it is false.
		the probability of rejecting Ho when it is true.
		the probablility of not rejecting Ho when it is true.
		the proability of rejecting Ho when it is false.

4 points

Question 11

1.

If we are testing for the difference between the means of 2
related populations with samples of n1 = 20 and n2 = 20, the number of degrees
of freedom is equal to

Answer

		39
		38
		19
		18

4 points

Question 12

1.

The statictical distribution used for testing the difference
between two population variances is the ___ distribution.

Answer

		t
		standardized normal
		binomial
		F

4 points

Question 13

1.

a “robust” test procedure is one which

Answer

		requires a sofphisticaed level of measurement.
		requires a semi-circular shaped population.
		is sensetive to slight violations in its assumptions.
		is insensetive to slight violations in its assumptions.

4 points

Question 14

1.

Why would you use the Tukey-Kramer procedure?

Answer

		to test for normality
		to test for homogeneity of variance
		to test for independence of errors
		to test for the differences in pairwise means

4 points

Question 15

1.

For a given level of significance, if the sample size is
increased, the power of the test will

Answer

		increase
		stay the same
		decrease

4 points

Question 16

1.

The standard error of the sample proportion is the largest when
the sample proportion reaches

Answer

		0.9
		0.8
		1
		0.5

4 points

Question 17

1.

An economist is interested in studying the incomes of consumers
in a particular region. The population standard deviation is know to be
$1,000. A random sample of 50 individuals resulted in an average income
of $15,000. What sample size would the economist need to use if he
wants a 95% confidence interval no wider than plus or minus $100?

Answer

		1486 individuals
		385 individuals
		126 individuals
		85 individuals

4 points

Question 18

1.

A 99% confidence intereval estimate can be interpreted to mean
that

Answer

		if all possible samples are taken and confidence interval estimates are developed, 99% of them would include the true population mean somewhere within their interval.
		we have 99% confidence that we have selected a sample whose interval does include the population mean.
		both of the above
		none of the above

4 points

Question 19

1.

The Y intercept (bo) represnts the

Answer

		the predicted value of Y when X = 0.
		the change in estimated average y per unit change in X.
		predicted value of Y.
		variation around the sample regression line.

4 points

Question 20

1.

The slope (b1) represents

Answer

		the predictied value of Y when X = 0
		the estimated average change in Y per unit change in X.
		the predicted value of Y.
		variation around the line of regression.

4 points

Question 21

1.

The least squares method minimizes which of the following?

Answer

		SSR
		SSE
		SST
		all the above

4 points

Question 22

1.

In performing a regression analysis involving two numerical
variables, we are ssuming:

Answer

		the variances of X and Y are equal.
		the variation around the line of regression is the same for each X value.
		that X and Y are independent.
		all of the above.

4 points

Question 23

1.

The strength of the linear relationship between to numerical
variables may be measured by the

Answer

		scatter diagram
		coefficient of correlation
		slope
		Y intercept

4 points

Question 24

1.

In a multiple regression mode, the value of the coefficient of
multiple determination

Answer

		has to fall between -1 and +1.
		has to fall between 0 and +1.
		has to fall between -1 and 0.
		can falll between any pair of real numbers.

4 points

Question 25

1.

When testing for independence in a contingency table with 3 rows
and 4 columns, there are ______ degrees of freedom.

Answer

		5
		6
		7
		12