# Lesson 3Y B Normal?Solidify Understanding

The enrollment at South Beach High School is . Mariana surveyed of her friends regarding where they prefer to eat lunch. She created the following two-way table showing her results.

Totals

School Cafeteria

Off Campus

Totals

Mariana plans to use her data to answer the following questions:

• Do students prefer to eat on campus or off campus?

• Is there a difference between grade levels for where students prefer to eat lunch?

### 1.

In Mariana’s sample, what percent of students prefer school lunch?

### 2.

What percent prefer to eat off campus?

### 3.

#### a.

For each grade level in her sample, determine the percent of students who prefer school lunch and the percent who prefer off-campus lunch.

Prefer School Lunch

Prefer Off Campus

#### b.

Do you notice anything unusual?

### 4.

Based on her sample, Mariana concludes that students at South Beach High School overall like school lunch. Do you agree or disagree? Why?

## Set

A company generates a mean monthly revenue of with a standard deviation of . In one given month, the company makes .

Find the -score.

### 6.

Assuming the company’s monthly revenue is normally distributed, what percent of the time does the company make more than this amount? Less than?

### 7.

What percent of the time does the company make between and ?

### 8.

If the company needs to make in order to break even, how likely in a given month is the company to make a profit?

On the Wechsler Adult Intelligence Scale, an average IQ is with a standard deviation of . (Source: https://openup.org/DcTE5Z)

### 9.

IQ scores between and are considered average. Assuming IQ scores follow a normal distribution, what percent of people are considered average?

### 10.

One measure of genius is an IQ score above . What percent of people are considered genius?

### 11.

Einstein had an IQ score of . What is his -score?

### 12.

What is the probability of an individual having a higher IQ than Einstein?

## Go

Without using technology, sketch the graph of the polynomial function with the given characteristics. Write the equation, if it’s not given.

### 13.

Degree:

Roots: multiplicity , ,

-intercept:

Equation:

Degree:

Equation: