AP Stats Final

which one of the following is not an example of data gathering

reaching a conclusion about the results of a reading program

which of these are categorical data

different types of anteaters

which of the following would most likely be graphed as a bar rather than a histogram

the ethnic distribution for a major city

complete a table of relative frequencies.the sum of the relative frequency column in such a table must be:

1

histograms are most useful in displaying

cumulative frequencies

estimate the relative frequency with countries of 20-22 days of no rainfall in the month of january

0.52

a symmetric distribution can't have which of the following distributions

a long tail on one side

The kind of sampling strategy least likely to produce statistics that are good estimates of population parameters is a

population Sample

six radio sinners are surveyed. Their favorite FM stations are 89.1,89.1,89.1,94.7,94.7 and 104.3 based on these data, you want to name the favorite station of a typical listener you should name.

The mode which is 89.1

calculate to the nearest whole number, the sample standard deviation of the set which is a sample from a larger population (71, 75, 65,73, 69,77 and 67)

4

all the following statements about the sample standard deviation are true, except

The standard deviation is negative when there are extreme values in the sample

The following hypothetical data set shows the purchase price in thousands for a sample of three bedroom two bathroom homes over the past year, compute the five number summary and create a modified box plot how many outliers are present in this distribution

3

why is the IKR considered to be a resistant statistic?

adding a new extreme observation has little effect on it

which measure of central tendency and measure of variation should be used with a normally distributed distribution

The mean and standard deviation

which of the following can stemplots show?

I,II, and III only

which of the following can affect outliers significantly

I, III, and IV

assume that normal curve A and normal curve B have identical population means. assume further that A has a greater population standard deviation than B. which curves, taller, and why?

5%

to the nearest whole number what percentile is associated with Z = 1.2?

88th percentile

what area to the nearest whole percent of the normal curve is located between Z = -0.6 and Z = 1.4?

64%

find the Z score for the low quartile of any normal curve around your answer to the nearest hundredth

-0.67

consider a multiple distribution with mue=65 and SD=4. A sample size of 950 is drawn from this population. Approximately how any of the 950 cases would you expect to find between 57 and 73.

all 950 cases

a normal probability plot:

graphs percentile ranks against z- scores

you believe that a normal probability plot of 30 data points provides evidence that the original data is normally distributed. if this is true, then the pattern of points on this normal probability plot is:

bell-shaped

all of the following statements are true about the normal distribution except

the normal curve crosses the x-axis at z-scores above 3.0 and below -3.0

the proper notation for a normal distribution with a mean of 250 and a SD of 25:

N(250, 25)

which of the following is true about the areas describes under the normal curve

fewer than one percent of the cases are located three standard deviations above or below then mean

in a normal distribution with a mean of 30 and a SD of 5, you'd find the largest proportion of cases between:

x=25 and x=35

when you have a normal distribution and you know that the area above a goven value is 0.35, you also know that:

none of the above

a normal curve table tells you that the probability lying below z=-1 is 0.1587. this can be interpreted as:

15.87% of the area of the curve lies at or below z=-1

you have two normally distributed populations: population A: mean=50 and SD=12 population B: mean=75 and SD=15.

are above 80 in population B

true or false: on the least regression line (x,y) always has a residual of zero.

true

true or false: all positive correlations indicate stronger relationships than all negative correlations.

flase

which of the following determines the signal of r?

whether the value of y decreases or increases as the value of x increases.

suppose that all data points are on the same line with a positive slope. what would r be for this sample.

r would be +1.0

a bivariate scatterplot has an r^2 of 0.85. this means:

85% of the variation in y explain the changes in x

Consider the data set A: (2,8), (3,6), (4,9), and (5,9). Which of the following is the proper interpretation of the coefficient of determination

thirty percent of the variation in y-values can be explained by variation in the x-values

a residual:

is how muacha reserved y-value is predicted

an outlier

usually has a strong effect on the correlation, coefficient and regression line and can also be an influential point

true or false: an R of -1.0 proves a strong cause an effect relationship between X and Y

false

influential points and outliers

sometimes have no effect on the regression line

A linear regression line indicates the amount of grams of the chemical CuSO4 the response variable why that dissolve in water at various temperatures in Celsius the explanatory variable X the least squares regression line is Y equals 10.14+0.5 1X give me the meaning of the slope of the regression line in the context of the problem

for each 1° rise in the temperature, you can dissolve 0.51 more grams of CuSO4

which of the following would indicate the strongest relationship between two variables?

r^2=-0.23

when, looking at a scatterplot of two variables, the variable along the horizontal axis is typically referred to as the

explanatory variable

The goal of the least squares regression is to compute a line that

minimizes the sum of the squared residuals

You've completed the following following lease squares regression line using a sample of college students Y equals 55+ 5XX equals hours of study per day and Y equals test score ranges from 0 to 100.

using the equation which is the predicted, test score for an individual who studies eight hours a day.

95

You've completed the following following lease squares regression line using a sample of college students Y equals 55+ 5XX equals hours of study per day and Y equals test score ranges from 0 to 100.

suppose the maximum number of hours of studying among the students in your sample is six if you use the equation to predict the test score of a student who studied eight hours a day your prediction would be considered an:

extrapolation

if the association between two variables, is exponential, which of the following is the general form of the regression equation for the transform data

Y = 8+ log (X^b)

suppose you make a scatterplot for the population of the United States, every decade from 1780 to 1990 the graph is exponential soda transform this relationship you can take the natural log rhythms of the response variable to find the regression equation for the these data, the resulting regression equation, r and r^2 is:

e^4.3764 people

some researchers were interested in whether the number of crimes committed during the summers related to the outdoor temperature the result of a survey of 150 municipal police departments revealed the following

The marginal distribution for crime rate below, normal, above, is

0.34, 0.37, 0.29

some researchers were interested in whether the number of crimes committed during the summers related to the outdoor temperature the result of a survey of 150 municipal police departments revealed the following

The conditional distribution of temperature by above average crime rate is:

0.12, 0.56, 0.33

you're given some bivariate XY data. You use your calculator to find the linear aggression line for the transform data. LNXLNY your calculator reports the equation of the least squares regression line to BY equals 0.2+0.4 X when X equals to the correct predicted value for Y is:

1.6117

The following table shows hypothetical data for two experimental treatments against two stages of cancer remission indicates a successful treatment rate is the proportion of remissions

which of the following is true?

when success rates for early in advanced, cancers are kept separate treatment a has a higher success rate, but when data from the two stages are combined treatment, B has a higher rate

The following table shows hypothetical data for two experimental treatments against two stages of cancer remission indicates a successful treatment rate is the proportion of remissions

what is the lurking variable when the data for early and advanced cancers are combined

Quality of hospital (good or poor)

The following table shows hypothetical data for two experimental treatments against two stages of cancer remission indicates a successful treatment rate is the proportion of remissions

which treatment is actually more effective

it depends on whether you're treating separate groups or one large group

which of the situations below probably does not have a lurking variable operating in someway

none of the above

which of the following is a characteristic of census?

it gathers data from every member of a population

an observational study based on survey data, concluded that individual who took more vitamin C were able to recover from the flu faster you want to replicate the study using an experimental approach. The treatment in this experiment might be:

The amount of vitamin C taken per day, 0 mg 1000 mg 2000 mg or 3000 mg

many statisticians say that the US census which attempts to count every population member directly, is significantly less accurate than account as estimated by random sampling. Why my account estimated from random samples be more accurate than a census.

A census often can't find every population member so some groups such as the homeless are often under represented

which of the following is the best representative sample of the adult population in the United States

simple, random sample of 1000 adults from across the country

A block is best described as

The use of chance to divide experimental units into groups

replication is best described as

The policy of repeating an experiment on different subjects to reduce trans variation, and to determine the generalized ability of the findings

double blind is the best described as

A design in which neither the experimenter, nor the subject knows who is in the treatment group and who is in the control group

The placebo effect is best described as

The tendency of subjects to respond favorably to any treatment

an experiment is conducted in which a series of tests are performed on pairs of identical, twins, who race separately a comparison of scores on each pair of twins, is used for analysis. This is best described as.

A matched pairs procedure

you're going to test two new varieties of fish food versus a commonly used fish food. You set up an experiment as follows 60 fish are randomly assigned to each of three different tanks. One tank is randomly selected to receive one of the new food another to receive the other new food and the third tank receive the common food. Fish growth is measured overtime. This is an example of.

A completely randomized design with a control group

Let's say you're interested in the effects on boys of different dosage levels of a new drug for the treatment of ADD. You set up an experiment to consider the factor of dosage with two levels 300 mg versus 500 mg what would be the different treatment groups of the experiment within each block

three groups: placebo drug/300 mg of new drug/500 mg of new drug

You've read a story in the New York Times, claiming that individuals to engage in aerobic exercises for at least an hour a day demonstrate fewer symptoms of depression. You read that and experiment, which was conducted in which a researcher first administered a survey on depression and self-esteem to 100 individuals then taught them some proper techniques of aerobic exercise. The 100 individuals were sent off to exercise at least one hour a day after two months the depression and self-esteem survey was administered again and showed that the depression symptoms declined and self-esteem increased The experimental design used here is a is a:

matched pairs before and after design

for semester project, a student needs to select a random sample of 10 students from a senior class of 250 he carefully numbers the class list from 0 to 249 and then uses a random number generator to obtain three digit random numbers the 10 unique numbers are his sample. He notices that they all belong to the same. AP calculus class. Another student claims this could not be a random sample which of the following is true.

whether the sample is a random sample or not is determined by the sampling method, not the results the method used here is valid

A primary research for one of her books sheer height distributed 100,000 questionnaires to women's groups 4500 women responded height found that 96% of women felt that if they give more emotional support to then they get from their husbands or boyfriends which of the following best describes her sample

voluntary response, Sample

an outlier: