MMW QUIZZES 3 and 4

SIGMA

Classify the data

lot areas of houses in a village

ratio

Classify the data

types of fruits

nominal

Classify the data

movie ratings (poor, fair, good, excellent)

ordinal

Classify the data

time of day on a 12-hour clock (3:00, 6:00, 9:00)

interval

Classify the data

Height of students in centimeters

ratio

what is statistics?

the science of collecting, analyzing, and interpreting data

which of the following is an example of descriptive statistics?

calculating the average age of studens in a class

what is the difference between a population and a sample?

a sample is a subset of a population, and it is always larger than a sample

which of the following is a qualitative variable?

gender

what type of graph is used to observe trends over time?

line graph

which of the following is NOT a measure of central tendency?

range

what is the mean of the dataset:

5, 10, 15, 20, 25

15

the median of a dataset is

the middle value when the data is sorted

what measure of central tendency is most affected by outliers?

mean

what is the mode of the dataset:

2, 4, 4, 6, 8, 8, 8, 10

8

which of the following best describes the first quartile (Q1)?

the value below which 25% of the data lies

in a dataset, the second quartile (Q2) is also known as

the median

which of the following statements is true about the interquartile range (IQR)?

IQR is the range between Q1 and Q3

which percentile corresponds to the median of a dataset?

50th percentile

which of the following a measure of variation or dispersion?

range

which of the following is true about the range of a dataset?

it is the difference between the highest and lowest values in the dataset

what does a larger standard deviation indicate about a dataset?

the data points are more spread out from the mean

if the variance of a dataset is 0, what can be concluded?

all values in the dataset are equal

the interquartile range (IQR) of a dataset is

the difference between the first and third quartiles (Q3 - Q1)

in a normal curve, the ordinate is highest at

mean

in normal distribution,

mean = median = mode

the shape of the normal curve depends upon the value of

standard deviation

the total area of the normal probability distribution is

1

A student’s score on a test is 90, and the class mean is 80 with an SD of 5.

What is the z score for the student’s score?

2

which of the following characteristics is true for a normal distribution?

it is symmetrical around the mean

in a standard normal distribution, the mean is

0

what percentage of the data lies within one standard deviation of the mean in a normal distribution?

68%

which of the following is the correct shape of a normal distribution curve?

bell-shaped

the median of a normal distribution corresponds to a value of Z is

0

in a normal distribution, Q1 = 20, and Q3 = 40, then the mean is equal to

30

what type of correlation is most appropriate to describe the data shown in the scatter plot?

negligible correlation

if the values of two variables move in the same direction,

the correlation is said to be positive

in a normal distribution, about 99.7% of the data lies within three standard deviations of the mean

true

the area under the normal distribution curve represents the probability of a random variable falling within a certain range

true

a negative correlation means that as one variable increases, the other variable decreases

true

in simple linear regression, if the correlation coefficient is close to 0, it suggests there is no linear relationship between the two variables

true

the mean of the standard normal distribution is 0

true

the total area under the normal curve is infinite

false

in simple linear regression, the independent variable and dependent variable must always have a linear relationship

false

a correlation coefficient of 0 indicates that there is no linear relationship between two variables

true

for a normal distribution, its mean, median, and mode are equal

true