stats midterm
the probability that the cowboys win the Big 12 men's basketball tournament this year is 0.4. The number 0.4 is a classical probability.
False
A pareto chart can be used to represents the frequency distribution for a categorical variable.
True
A random variable is a numerical description of a probability experiment.
True
A time series graph would be appropriate for displaying the number of boys on an 8th grade football team over the last 5 years.
True
All students in a class are assigned a number and a random number table is used to select 5 of them to interview. This is a random sample.
True
Consider rolling two 6 sided dice. The events that they sum to 3 and one of the dice rolls is a 5 are mutually exclusive.
True
In a local tennis club, 15% of the men are left-handed. This is an example of a descriptive statistic
True
The heart rate of men with a beard is compared to the heart of men without a beard. the dependent variable is heart rate.
True
The law of large number states that the probability of an event is the proportion pf times that it occurs if the experiment is run indefinitely
True
Z scores and percentiles are measure of position
True
the area under a normal curve that lies within 2 standard deviations of the mean is approximately 0.95
True
the weight of offensive linemen on a football team is a continuous random variable
True
continuous or discrete the lengths of phone calls
continuous
continuous or discrete the time spent watching a movie
continuous
classify the statement as an example of classical probability, empirical probability, or subjective probability. The probability that a person will catch the 6 o'clock news is 0.15
empirical
The central limit theorem states that the sample mean has a normal distribution only if the data are sampled from a symmetric population
false
let x be the number of times that i flip a coin until i get two heads in a row. Then x has a binomial distribution
false
the area under the part of a normal curve that lies within 3 standard deviations of the mean is approximately 0.95.
false (2 standard deviations)
an election campaign would like to compare the number of registered females to the number of registered males in a certain county. a histogram could be used to display this distribution.
false (bar graph or pie chart would work)
an education professor compares the college GPA among students with low socioeconomic status to students with high socioeconomic status. The independent variable in this study is college GPA
false (dependent)
a salary survey reveals that 1/2 of osu students wth part time jobs earn at least $10 per hour. The measure of central tendency used to describe salaries here is the mean
false (median)
a survey was taken to determine how many students were struggling with anxiety or depression. This study is an experimental study.
false (observational)
eye color and gender are examples of quantitative variables
false (qualitative)
the central limit theorem says that the distribution of the sample means will be approximately normal when the sample is small
false (when the sample is large)
Historical dates from 800 BC to 1800 AD. (nominal-level, ordinal-level, interval-level, ratio-level)
interval-level
observational or experimental study? A survey of students enrolled in a college statistics class was taken to see how many hours per week a student studies.
observational
observational or experimental study? a study was conducted to see if employees who work nights sleep less hours than employees who work days
observational
high school class rank (nominal-level, ordinal-level, interval-level, ratio-level)
ordinal-level
maximum weight per axle for commercial trucks
quantitative
number of bananas in a bunch at several local supermarkets
quantitative
what sampling method was used? A game show assigns all audience members a number and uses a random number generator to select the contestants
random
what sampling method was used? cattle tag numbers at a livestock auction are selected using a random number generator. the cattle are then tested for mad cow disease
random
amounts of money spent on a medical checkup. (nominal-level, ordinal-level, interval-level, ratio-level)
ratio-level
----------- is the science of conducting studies to collect, organize, summarize, analyze, and draw conclusions from data.
statistics
all the names of students in a debate class are put into a hat. the teacher draws two names out of the hate to be team captain. the sampling method used to choose captains was random.
true
consider rolling a 6 sided dice 10 times and let x be the number of times that an odd number is rolled. Then the mean of x is 5
true
let x be the distance between potholes on a highway. x is a continuous variable
true
suppose we select a student at random at osu. consider the event that the student is a male and the student is a business major. These two events are not mutually exclusive.
true
the mean is greater than the median for skewed right distribution
true
the mean, median, and mode are measures of central tendency
true
the multiplication rule for independent event says that P(A and B)= P(A)xP(B)
true
the normal distribution is symmetric about its mean
true
the probability of rolling 3 heads in three coin tosses is 1/8. the number 1/8 is a classical probability.
true
the standard deviation of the sample mean is called the standard error
true
the standard normal distribution has mean 0 and variance 1
true
a probability experiment is conducted. which of these CANNOT be considered a probability outcome?
-2/3 , 110%, -0.3, 1.15
which of the following are characteristics of a normal distribution
-the mean, median, and mode are located at the center of the distribution. -the normal distribution curve is unimodal. -the area under the part of a normal curve that lies within 2 standard deviations of the mean is approximately 0.95. -the total area under the normal distribution curve is 1.00 -the area under the part of a normal bell curve that lies within 1 standard deviation of the mean is approx. 0.68 -a normal distribution curve is bell shaped
The number of calories in a hotdog is an example of a qualitative variable.
False
A study concludes that the most common fear today is the fear of speaking in public. The median was the measure of central tendency used in the study.
False
In an observational study, the researcher manipulates one of the variables and tries to determine how the manipulation influences other variables.
False
The mean should be used to describe the center of a data set when there are extreme observations
False