# Lesson 5Would You Like to Try a Sample?Develop Understanding

When collecting data, statisticians are often interested in making predictions. Sometimes the only thing they want to know is if one variable is related or associated with another variable. (Can you predict one variable given information on the other one? This is called correlation.) Other times, they want to determine if one variable actually causes a change in another variable. For each example, decide whether the variables represent correlation, or if you think one variable would cause the other to change, representing causation.

### 1.

As the amount of food Ollie the elephant eats increases, her weight also increases. (correlation/causation)

### 2.

As Popsicle sales go up in the summer, the number of people drowning also increases. (correlation/causation)

### 3.

As Erika’s feet grow longer, she grows taller. (correlation/causation)

### 4.

As Tabatha gets older, her reading score improves in school. (correlation/causation)

## Set

For each scenario below, identify the population, sample, and parameter of interest.

### 5.

The local school board wants to get parents to evaluate teachers. They select and find that approve of their child’s teacher.

Population

Sample

Parameter

### 6.

Jarret wants to know the average height of the students in his school. There are in his high school; he finds the heights of .

Population

Sample

Parameter

### 7.

A government official is interested in the percent of people at JFK airport who are searched by security. He watches go through security and observes who are searched.

Population

Sample

Parameter

For each scenario, identify what type of sampling was used to obtain the sample. Explain whether or not you think the sample will be representative of the population it was sampled from.

### 8.

Elvira surveys the first in the lunch line to determine if students at the school are satisfied with school lunch.

Type of sample:

#### b.

Representative? Explain.

### 9.

Elvira selects every 5th student in the lunch line to determine if students at the school are satisfied with school lunch.

Type of sample:

#### b.

Representative? Explain.

### 10.

Elvira randomly selects different tables in the lunchroom and surveys every student on the table to determine if students at the school are satisfied with school lunch.

Type of sample:

#### b.

Representative? Explain.

### 11.

Elvira assigns every student in the school a number and randomly selects to survey to determine if students at the school are satisfied with school lunch.

Type of sample:

#### b.

Representative? Explain.

### 12.

Elvira wants to determine if students are satisfied with school lunch. She leaves surveys on a table for students to answer as they walk by.

Type of sample:

#### b.

Representative? Explain.

### 13.

Elvira wants to determine if students are satisfied with school lunch. She wants to include input from each grade level at the high school. She randomly surveys , , , and .

Type of sample:

#### b.

Representative? Explain.

## Go

For each function, identify the amplitude, period, horizontal shift, and the vertical shift.

### 14.

Amplitude:

Period:

Horizontal shift:

Vertical shift:

### 15.

Amplitude:

Period:

Horizontal shift:

Vertical shift:

### 16.

Graph at least one full period of .