stats 3

A local bakery sells an average of 5 cakes each day. What is the probability of selling 40 cakes in a week?

4.5%

What is meant by coding for categorical variables?

Creating a dummy numeric variable

Which of the following is an example of a piece of categorical data?

Ethnicity

Jia has a sample size of 15. He wants to be able to make inferences about the entire population based on his work. What should he do when calculating his confidence interval?

He should use the t-table to compare calculations because this distribution uses fatter than normal tails under the normal curve to approximate the general population standard deviation.

Kasey (a girl) and Michael (a boy) are auditioning for a reality TV show about singing. The show's producers want to choose one boy and one girl. Including Kasey and Michael, there are 4 girls and 2 boys auditioning. Is the event of Kasey being selected independent from the event of Michael being selected, or are the events dependent? Also, what is the probability that the producers will select Kasey and Michael for the show?

Independent; 13%

What is the difference between the upper quartile value and the lower quartile value?

Interquartile range

What do we call a prediction where a variable (y) is dependent on a second variable (x) based on the regression equation of a given set of data?

Linear regression

Where is the normal distribution curve at its highest point?

Mean

Which of the following is the number that appears most often?

Mode.

What are the two hypotheses that must be created when performing hypothesis testing for a proportion?

Null and alternate.

A coach records the levels of ability in martial arts of various kids. What type of data is this?

Ordinal

Sarah performs an experiment to determine the best amount of sun and water for a certain type of plant. She varies the amount of water the plants get each day and also how much time they are in the sun. At the end of six weeks, she measures how tall each plant is. Which of these is an example of an interaction effect that this experiment might detect?

Plants that receive more sunlight also require more water

What is the term for the variability of individual observations around their mean?

Standard deviation

What does r^2 represent?

The coefficient of determination

Jim's Solutions Inc has recently expanded into a new market after seeing extremely favorable results in his existing market on his decision tree. What common mistake is likely to be at fault for this unexpectedly negative result in the new market?

The decision tree used by Jim's Solutions was based on, or relied on, raw data that was inaccurate.

When are t-tests most appropriate to use?

all of the the answers are correct

A business owner is collecting data about how many products they sell in each of three sizes: small, medium, and large. The data the owner is collecting is _____ data.

attribute

Data can be described as being _____ when it is dynamic and changes frequently.

continuous

Simple random sampling is usually done _____.

without replacement