# Histograms

If you want to analyze numerical data that has been sorted into equal intervals, histograms can be helpful visualization tools. A histogram is a special type of bar graph displaying data in equal intervals where adjacent bars touch one another but do not overlap. Displaying data this way makes it easier to see its frequency distribution and how many pieces of data are in each interval. Here is an example:

In this article, we'll explore how to draw histograms and interpret the data they present. Let's get started!

## Drawing histograms: A step-by-step guide

The first step in drawing a histogram is collecting the raw data we want to depict. For example, the frequency table below shows the admission cost of various theme parks:

Costs | ($) | Frequency |
---|---|---|

7-14 | ///// | 5 |

15-22 | /////// | 7 |

23-30 | //// | 4 |

31-38 | 0 | |

39-46 | // | 2 |

Okay, now we have our data. Next, draw and label a horizontal and vertical axis to serve as the base of our histogram. The intervals from the frequency table above (under the Costs section) should appear on the horizontal axis, with an interval of 2 units on the vertical axis (2, 4, 6, 8, etc.). Be sure to include a title at the top of the histogram and identify what is represented by each axis!

The last step is when we actually draw our bars. Our scale doesn't specifically list any odd numbers, so draw carefully so your bars are halfway between two even numbers instead of being too short or too long. Your bars should also be touching each other, except for the 31-38 interval where we're intentionally graphing zero. The final product should look something like this:

## Interpreting histograms

Drawing histograms is great, but some problems will give us a histogram and ask questions about the data. For instance, the following histogram reveals the highest level of education completed by the employees of a local store:

When working with problems like this, it's important to watch out for keywords such as "at least," "in all," and "except" so you're focusing on the right information. For example, the answer would be 200 if we were asked about how many employees the store had "in all" and 190 if we were looking for all employees "except" those with graduate degrees.

## Histograms practice questions

a. Draw a histogram based on the following data:

How Long Middle School Students Spend on Homework Per Night

Time(min) | Frequency |
---|---|

0-30 | 5 |

31-60 | 25 |

61-90 | 20 |

91-120 | 10 |

We should put the time intervals on the horizontal axis and the frequencies on the vertical axis, using a scale of 5 on the latter since all of our numbers are divisible by 5. Our title can simply be the title of the chart (How Long Middle School Students Spend on Homework Per Night), and we need to specify the time (minutes) for the horizontal axis and the number of students for the vertical axis. Finally, carefully draw bars to correctly indicate the number of students falling into each range.

b. Using the histogram you drew above, how many students spend more than an hour on their homework?

If Ashton outscored 73 of his classmates on this exam, what could his score have been?

## Topics related to the Histograms

Developing a Probability Distribution from Empirical Data

## Flashcards covering the Histograms

Common Core: 6th Grade Math Flashcards

## Practice tests covering the Histograms

MAP 6th Grade Math Practice Tests

## Get help with histograms today

Histograms help students interpret data, one of the most important skills to develop in math class. If the student in your life is drawing sloppy graphs they cannot interpret or getting confused by intervals and frequencies, an experienced math tutor can help them identify the root cause of their learning obstacles and address them directly. A 1-on-1 tutor can also provide a private learning environment where it's okay to make mistakes to facilitate the educational process. Contact the friendly Educational Directors at Varsity Tutors today to learn more about the benefits of private instruction and to get signed up.

- CLEP American Government Test Prep
- FAA - Federal Aviation Administration examination Courses & Classes
- TASC Social Studies Tutors
- Catalan Tutors
- Nursing/NCLEX Tutors
- Middle School Science Tutors
- Minnesota Bar Exam Courses & Classes
- Series 52 Test Prep
- G Suite Tutors
- Certified ScrumMaster Test Prep
- CSRM - Certified School Risk Manager Courses & Classes
- CCNA Data Center - Cisco Certified Network Associate-Data Center Courses & Classes
- Chemistry REGENTS Tutors
- NPTE - National Physical Therapy Examination Tutors
- French Courses & Classes
- CLEP English Literature Courses & Classes
- ACT Writing Test Prep
- Nebraska Bar Exam Courses & Classes
- IB Information Technology in a Global Society HL Tutors
- Thesis Writing Tutors