Algebra 2
Algebra 2
1st Edition
ISBN: 9780078884825
Author: McGraw-Hill/Glencoe
Publisher: Glencoe/McGraw-Hill School Pub Co
bartleby

Concept explainers

Inverse Normal Distribution
The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of tw…
Mean, Median, Mode
It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency o…
Z-Scores
A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow compar…
bartleby

Videos

Question
Book Icon
Chapter 12, Problem 4PT
To determine

To verify:-whether the given survey will produce a random sample or not.

Expert Solution & Answer
Check Mark

Answer to Problem 4PT

Yes

Explanation of Solution

Given information :

We know that, a teacher selects names of 5 students from a hat to determine who gives their speeches in class that day.

A random sample is a subset of individuals chosen from a larger set. Each individual is chosen randomly and entirely by chance, hence this survey produces a random sample.

Previous
Chapter 12, Problem 3PT
Next
Chapter 12, Problem 5PT

Chapter 12 Solutions

Algebra 2

Ch. 12.1 - Prob. 1ACYPCh. 12.1 - Prob. 1BCYPCh. 12.1 - Prob. 1CCYPCh. 12.1 - Prob. 2ACYPCh. 12.1 - Prob. 2BCYPCh. 12.1 - Prob. 2CCYPCh. 12.1 - Prob. 3CYPCh. 12.1 - Prob. 4CYPCh. 12.1 - Prob. 5CYPCh. 12.1 - Prob. 1CYU
Ch. 12.1 - Prob. 2CYUCh. 12.1 - Prob. 3CYUCh. 12.1 - Prob. 4CYUCh. 12.1 - Prob. 5CYUCh. 12.1 - Prob. 6CYUCh. 12.1 - Prob. 7CYUCh. 12.1 - Prob. 8CYUCh. 12.1 - Prob. 9CYUCh. 12.1 - Prob. 10PPSCh. 12.1 - Prob. 11PPSCh. 12.1 - Prob. 12PPSCh. 12.1 - Prob. 13PPSCh. 12.1 - Prob. 14PPSCh. 12.1 - Prob. 15PPSCh. 12.1 - Prob. 16PPSCh. 12.1 - Prob. 17PPSCh. 12.1 - Prob. 18PPSCh. 12.1 - Prob. 19PPSCh. 12.1 - Prob. 20PPSCh. 12.1 - Prob. 21PPSCh. 12.1 - Prob. 22PPSCh. 12.1 - Prob. 23PPSCh. 12.1 - Prob. 24PPSCh. 12.1 - Prob. 25PPSCh. 12.1 - Prob. 26PPSCh. 12.1 - Prob. 27PPSCh. 12.1 - Prob. 28HPCh. 12.1 - Prob. 29HPCh. 12.1 - Prob. 30HPCh. 12.1 - Prob. 31HPCh. 12.1 - Prob. 32HPCh. 12.1 - Prob. 33HPCh. 12.1 - Prob. 34HPCh. 12.1 - Prob. 35HPCh. 12.1 - Prob. 36HPCh. 12.1 - Prob. 37STPCh. 12.1 - Prob. 38STPCh. 12.1 - Prob. 39STPCh. 12.1 - Prob. 40STPCh. 12.1 - Prob. 41STPCh. 12.1 - Prob. 42STPCh. 12.1 - Prob. 43STPCh. 12.1 - Prob. 44STPCh. 12.1 - Prob. 45STPCh. 12.1 - Prob. 46STPCh. 12.1 - Prob. 47STPCh. 12.1 - Prob. 48STPCh. 12.1 - Prob. 49STPCh. 12.1 - Prob. 50STPCh. 12.1 - Prob. 51STPCh. 12.1 - Prob. 52STPCh. 12.1 - Prob. 53STPCh. 12.1 - Prob. 54STPCh. 12.1 - Prob. 55STPCh. 12.1 - Prob. 56STPCh. 12.1 - Prob. 57STPCh. 12.1 - Prob. 58STPCh. 12.1 - Prob. 59STPCh. 12.1 - Prob. 60SCh. 12.1 - Prob. 61SCh. 12.2 - Prob. 1CYPCh. 12.2 - Prob. 2ACYPCh. 12.2 - Prob. 2BCYPCh. 12.2 - Prob. 3ACYPCh. 12.2 - Prob. 3BCYPCh. 12.2 - Prob. 4ACYPCh. 12.2 - Prob. 4BCYPCh. 12.2 - Prob. 1CYUCh. 12.2 - Prob. 2CYUCh. 12.2 - Prob. 3CYUCh. 12.2 - Prob. 4CYUCh. 12.2 - Prob. 5CYUCh. 12.2 - Prob. 6CYUCh. 12.2 - Prob. 7CYUCh. 12.2 - Prob. 8CYUCh. 12.2 - Prob. 9CYUCh. 12.2 - Prob. 10CYUCh. 12.2 - Prob. 11PPSCh. 12.2 - Prob. 12PPSCh. 12.2 - Prob. 13PPSCh. 12.2 - Prob. 14PPSCh. 12.2 - Prob. 15PPSCh. 12.2 - Prob. 16PPSCh. 12.2 - Prob. 17PPSCh. 12.2 - Prob. 18PPSCh. 12.2 - Prob. 19PPSCh. 12.2 - Prob. 20PPSCh. 12.2 - Prob. 21PPSCh. 12.2 - Prob. 22PPSCh. 12.2 - Prob. 23PPSCh. 12.2 - Prob. 24PPSCh. 12.2 - Prob. 25PPSCh. 12.2 - Prob. 26PPSCh. 12.2 - Prob. 27PPSCh. 12.2 - Prob. 29HPCh. 12.2 - Prob. 30HPCh. 12.2 - Prob. 31HPCh. 12.2 - Prob. 32HPCh. 12.2 - Prob. 33HPCh. 12.2 - Prob. 34HPCh. 12.2 - Prob. 35HPCh. 12.2 - Prob. 36HPCh. 12.2 - Prob. 37HPCh. 12.2 - Prob. 38STPCh. 12.2 - Prob. 39STPCh. 12.2 - Prob. 40STPCh. 12.2 - Prob. 41STPCh. 12.2 - Prob. 42SCh. 12.2 - Prob. 43SCh. 12.2 - Prob. 44SCh. 12.2 - Prob. 45SCh. 12.3 - Prob. 1CYPCh. 12.3 - Prob. 2CYPCh. 12.3 - Prob. 3CYPCh. 12.3 - Prob. 1CYUCh. 12.3 - Prob. 2CYUCh. 12.3 - Prob. 3CYUCh. 12.3 - Prob. 4CYUCh. 12.3 - Prob. 5CYUCh. 12.3 - Prob. 6CYUCh. 12.3 - Prob. 7PPSCh. 12.3 - Prob. 8PPSCh. 12.3 - Prob. 9PPSCh. 12.3 - Prob. 10PPSCh. 12.3 - Prob. 11PPSCh. 12.3 - Prob. 12PPSCh. 12.3 - Prob. 13PPSCh. 12.3 - Prob. 14PPSCh. 12.3 - Prob. 15PPSCh. 12.3 - Prob. 16PPSCh. 12.3 - Prob. 17PPSCh. 12.3 - Prob. 18PPSCh. 12.3 - Prob. 19PPSCh. 12.3 - Prob. 20PPSCh. 12.3 - Prob. 21PPSCh. 12.3 - Prob. 22PPSCh. 12.3 - Prob. 23HPCh. 12.3 - Prob. 24HPCh. 12.3 - Prob. 25HPCh. 12.3 - Prob. 26HPCh. 12.3 - Prob. 27HPCh. 12.3 - Prob. 28HPCh. 12.3 - Prob. 29HPCh. 12.3 - Prob. 30HPCh. 12.3 - Prob. 31HPCh. 12.3 - Prob. 32STPCh. 12.3 - Prob. 33STPCh. 12.3 - Prob. 34STPCh. 12.3 - Prob. 35STPCh. 12.3 - Prob. 36SCh. 12.3 - Prob. 37SCh. 12.3 - Prob. 38SCh. 12.3 - Prob. 39SCh. 12.3 - Prob. 40SCh. 12.3 - Prob. 41SCh. 12.4 - Prob. 1CYPCh. 12.4 - Prob. 2CYPCh. 12.4 - Prob. 3CYPCh. 12.4 - Prob. 4ACYPCh. 12.4 - Prob. 4BCYPCh. 12.4 - Prob. 4CCYPCh. 12.4 - Prob. 5CYPCh. 12.4 - Prob. 1CYUCh. 12.4 - Prob. 2CYUCh. 12.4 - Prob. 3CYUCh. 12.4 - Prob. 4CYUCh. 12.4 - Prob. 5CYUCh. 12.4 - Prob. 6PPSCh. 12.4 - Prob. 7PPSCh. 12.4 - Prob. 8PPSCh. 12.4 - Prob. 9PPSCh. 12.4 - Prob. 10PPSCh. 12.4 - Prob. 11PPSCh. 12.4 - Prob. 12PPSCh. 12.4 - Prob. 13PPSCh. 12.4 - Prob. 14PPSCh. 12.4 - Prob. 15PPSCh. 12.4 - Prob. 16PPSCh. 12.4 - Prob. 17PPSCh. 12.4 - Prob. 18PPSCh. 12.4 - Prob. 19PPSCh. 12.4 - Prob. 20PPSCh. 12.4 - Prob. 21PPSCh. 12.4 - Prob. 22PPSCh. 12.4 - Prob. 23PPSCh. 12.4 - Prob. 24PPSCh. 12.4 - Prob. 25PPSCh. 12.4 - Prob. 26PPSCh. 12.4 - Prob. 27PPSCh. 12.4 - Prob. 28PPSCh. 12.4 - Prob. 29PPSCh. 12.4 - Prob. 30PPSCh. 12.4 - Prob. 31PPSCh. 12.4 - Prob. 32PPSCh. 12.4 - Prob. 33STPCh. 12.4 - Prob. 34STPCh. 12.4 - Prob. 35STPCh. 12.4 - Prob. 36STPCh. 12.4 - Prob. 37STPCh. 12.4 - Prob. 38STPCh. 12.4 - Prob. 39STPCh. 12.4 - Prob. 40STPCh. 12.4 - Prob. 41STPCh. 12.4 - Prob. 42STPCh. 12.4 - Prob. 43STPCh. 12.4 - Prob. 44STPCh. 12.4 - Prob. 45STPCh. 12.4 - Prob. 46STPCh. 12.4 - Prob. 47STPCh. 12.4 - Prob. 48SCh. 12.4 - Prob. 49SCh. 12.4 - Prob. 50SCh. 12.4 - Prob. 51SCh. 12.4 - Prob. 52SCh. 12.4 - Prob. 53SCh. 12.5 - Prob. 1CYPCh. 12.5 - Prob. 2CYPCh. 12.5 - Prob. 3CYPCh. 12.5 - Prob. 4CYPCh. 12.5 - Prob. 1CYUCh. 12.5 - Prob. 2CYUCh. 12.5 - Prob. 3CYUCh. 12.5 - Prob. 4PPSCh. 12.5 - Prob. 5PPSCh. 12.5 - Prob. 6PPSCh. 12.5 - Prob. 7PPSCh. 12.5 - Prob. 8PPSCh. 12.5 - Prob. 9PPSCh. 12.5 - Prob. 10PPSCh. 12.5 - Prob. 11PPSCh. 12.5 - Prob. 12PPSCh. 12.5 - Prob. 13PPSCh. 12.5 - Prob. 14PPSCh. 12.5 - Prob. 15PPSCh. 12.5 - Prob. 16HPCh. 12.5 - Prob. 17HPCh. 12.5 - Prob. 18HPCh. 12.5 - Prob. 19HPCh. 12.5 - Prob. 21HPCh. 12.5 - Prob. 22HPCh. 12.5 - Prob. 23HPCh. 12.5 - Prob. 24HPCh. 12.5 - Prob. 25HPCh. 12.5 - Prob. 26HPCh. 12.5 - Prob. 27STPCh. 12.5 - Prob. 28STPCh. 12.5 - Prob. 29STPCh. 12.5 - Prob. 30STPCh. 12.5 - Prob. 31STPCh. 12.5 - Prob. 32STPCh. 12.5 - Prob. 33SCh. 12.5 - Prob. 34SCh. 12.5 - Prob. 35SCh. 12.5 - Prob. 36SCh. 12.5 - Prob. 1ECh. 12.5 - Prob. 2ECh. 12.6 - Prob. 1CYPCh. 12.6 - Prob. 2CYPCh. 12.6 - Prob. 1CYUCh. 12.6 - Prob. 2CYUCh. 12.6 - Prob. 3CYUCh. 12.6 - Prob. 4CYUCh. 12.6 - Prob. 5CYUCh. 12.6 - Prob. 6CYUCh. 12.6 - Prob. 7CYUCh. 12.6 - Prob. 8CYUCh. 12.6 - Prob. 9CYUCh. 12.6 - Prob. 10CYUCh. 12.6 - Prob. 11PPSCh. 12.6 - Prob. 12PPSCh. 12.6 - Prob. 13PPSCh. 12.6 - Prob. 14PPSCh. 12.6 - Prob. 15PPSCh. 12.6 - Prob. 16PPSCh. 12.6 - Prob. 17PPSCh. 12.6 - Prob. 18PPSCh. 12.6 - Prob. 19PPSCh. 12.6 - Prob. 20PPSCh. 12.6 - Prob. 21PPSCh. 12.6 - Prob. 22PPSCh. 12.6 - Prob. 23PPSCh. 12.6 - Prob. 24PPSCh. 12.6 - Prob. 25PPSCh. 12.6 - Prob. 26PPSCh. 12.6 - Prob. 27PPSCh. 12.6 - Prob. 28PPSCh. 12.6 - Prob. 29HPCh. 12.6 - Prob. 30HPCh. 12.6 - Prob. 31HPCh. 12.6 - Prob. 33HPCh. 12.6 - Prob. 34HPCh. 12.6 - Prob. 35HPCh. 12.6 - Prob. 36HPCh. 12.6 - Prob. 37HPCh. 12.6 - Prob. 38STPCh. 12.6 - Prob. 39STPCh. 12.6 - Prob. 40STPCh. 12.6 - Prob. 41STPCh. 12.6 - Prob. 42STPCh. 12.6 - Prob. 43STPCh. 12.6 - Prob. 44STPCh. 12.6 - Prob. 45STPCh. 12.6 - Prob. 46STPCh. 12.6 - Prob. 47STPCh. 12.6 - Prob. 48STPCh. 12.6 - Prob. 49SCh. 12.6 - Prob. 50SCh. 12.6 - Prob. 51SCh. 12.7 - Prob. 1CYPCh. 12.7 - Prob. 2CYPCh. 12.7 - Prob. 3CYPCh. 12.7 - Prob. 4CYPCh. 12.7 - Prob. 5CYPCh. 12.7 - Prob. 6CYPCh. 12.7 - Prob. 7CYPCh. 12.7 - Prob. 8CYPCh. 12.7 - Prob. 1CYUCh. 12.7 - Prob. 2CYUCh. 12.7 - Prob. 3CYUCh. 12.7 - Prob. 4CYUCh. 12.7 - Prob. 5CYUCh. 12.7 - Prob. 6CYUCh. 12.7 - Prob. 7PPSCh. 12.7 - Prob. 8PPSCh. 12.7 - Prob. 9PPSCh. 12.7 - Prob. 10PPSCh. 12.7 - Prob. 11PPSCh. 12.7 - Prob. 12PPSCh. 12.7 - Prob. 13PPSCh. 12.7 - Prob. 14PPSCh. 12.7 - Prob. 15PPSCh. 12.7 - Prob. 16PPSCh. 12.7 - Prob. 17PPSCh. 12.7 - Prob. 18PPSCh. 12.7 - Prob. 19PPSCh. 12.7 - Prob. 20PPSCh. 12.7 - Prob. 21PPSCh. 12.7 - Prob. 22PPSCh. 12.7 - Prob. 23PPSCh. 12.7 - Prob. 24PPSCh. 12.7 - Prob. 25PPSCh. 12.7 - Prob. 26PPSCh. 12.7 - Prob. 27PPSCh. 12.7 - Prob. 28PPSCh. 12.7 - Prob. 29PPSCh. 12.7 - Prob. 30PPSCh. 12.7 - Prob. 31PPSCh. 12.7 - Prob. 32PPSCh. 12.7 - Prob. 33PPSCh. 12.7 - Prob. 34PPSCh. 12.7 - Prob. 35PPSCh. 12.7 - Prob. 36PPSCh. 12.7 - Prob. 37PPSCh. 12.7 - Prob. 38PPSCh. 12.7 - Prob. 39PPSCh. 12.7 - Prob. 40PPSCh. 12.7 - Prob. 41PPSCh. 12.7 - Prob. 42HPCh. 12.7 - Prob. 43HPCh. 12.7 - Prob. 44HPCh. 12.7 - Prob. 46HPCh. 12.7 - Prob. 47HPCh. 12.7 - Prob. 48HPCh. 12.7 - Prob. 49HPCh. 12.7 - Prob. 50HPCh. 12.7 - Prob. 51HPCh. 12.7 - Prob. 52STPCh. 12.7 - Prob. 53STPCh. 12.7 - Prob. 54STPCh. 12.7 - Prob. 55STPCh. 12.7 - Prob. 56STPCh. 12.7 - Prob. 57STPCh. 12.7 - Prob. 58STPCh. 12.7 - Prob. 59STPCh. 12.7 - Prob. 60STPCh. 12.7 - Prob. 61STPCh. 12.7 - Prob. 62STPCh. 12.7 - Prob. 63STPCh. 12.7 - Prob. 64STPCh. 12.7 - Prob. 65STPCh. 12.7 - Prob. 66STPCh. 12.7 - Prob. 67STPCh. 12.7 - Prob. 68STPCh. 12.7 - Prob. 69STPCh. 12.7 - Prob. 70STPCh. 12.7 - Prob. 71STPCh. 12.7 - Prob. 72SCh. 12 - Prob. 1QCCh. 12 - Prob. 2QCCh. 12 - Prob. 3QCCh. 12 - Prob. 4QCCh. 12 - Prob. 5QCCh. 12 - Prob. 6QCCh. 12 - Prob. 7QCCh. 12 - Prob. 8QCCh. 12 - Prob. 9QCCh. 12 - Prob. 10QCCh. 12 - Prob. 11QCCh. 12 - Prob. 12QCCh. 12 - Prob. 13QCCh. 12 - Prob. 14QCCh. 12 - Prob. 1MCQCh. 12 - Prob. 2MCQCh. 12 - Prob. 3MCQCh. 12 - Prob. 4MCQCh. 12 - Prob. 5MCQCh. 12 - Prob. 6MCQCh. 12 - Prob. 7MCQCh. 12 - Prob. 8MCQCh. 12 - Prob. 9MCQCh. 12 - Prob. 10MCQCh. 12 - Prob. 11MCQCh. 12 - Prob. 12MCQCh. 12 - Prob. 13MCQCh. 12 - Prob. 14MCQCh. 12 - Prob. 15MCQCh. 12 - Prob. 1SGRCh. 12 - Prob. 2SGRCh. 12 - Prob. 3SGRCh. 12 - Prob. 4SGRCh. 12 - Prob. 5SGRCh. 12 - Prob. 6SGRCh. 12 - Prob. 7SGRCh. 12 - Prob. 8SGRCh. 12 - Prob. 9SGRCh. 12 - Prob. 10SGRCh. 12 - Prob. 11SGRCh. 12 - Prob. 12SGRCh. 12 - Prob. 13SGRCh. 12 - Prob. 14SGRCh. 12 - Prob. 15SGRCh. 12 - Prob. 16SGRCh. 12 - Prob. 17SGRCh. 12 - Prob. 18SGRCh. 12 - Prob. 19SGRCh. 12 - Prob. 20SGRCh. 12 - Prob. 21SGRCh. 12 - Prob. 22SGRCh. 12 - Prob. 23SGRCh. 12 - Prob. 24SGRCh. 12 - Prob. 25SGRCh. 12 - Prob. 26SGRCh. 12 - Prob. 27SGRCh. 12 - Prob. 28SGRCh. 12 - Prob. 29SGRCh. 12 - Prob. 30SGRCh. 12 - Prob. 31SGRCh. 12 - Prob. 32SGRCh. 12 - Prob. 33SGRCh. 12 - Prob. 34SGRCh. 12 - Prob. 35SGRCh. 12 - Prob. 36SGRCh. 12 - Prob. 37SGRCh. 12 - Prob. 38SGRCh. 12 - Prob. 39SGRCh. 12 - Prob. 40SGRCh. 12 - Prob. 41SGRCh. 12 - Prob. 42SGRCh. 12 - Prob. 43SGRCh. 12 - Prob. 44SGRCh. 12 - Prob. 1PTCh. 12 - Prob. 2PTCh. 12 - Prob. 3PTCh. 12 - Prob. 4PTCh. 12 - Prob. 5PTCh. 12 - Prob. 6PTCh. 12 - Prob. 7PTCh. 12 - Prob. 8PTCh. 12 - Prob. 9PTCh. 12 - Prob. 10PTCh. 12 - Prob. 11PTCh. 12 - Prob. 12PTCh. 12 - Prob. 13PTCh. 12 - Prob. 14PTCh. 12 - Prob. 15PTCh. 12 - Prob. 16PTCh. 12 - Prob. 17PTCh. 12 - Prob. 18PTCh. 12 - Prob. 19PTCh. 12 - Prob. 20PTCh. 12 - Prob. 21PTCh. 12 - Prob. 22PTCh. 12 - Prob. 1ECh. 12 - Prob. 2ECh. 12 - Prob. 1STPCh. 12 - Prob. 2STPCh. 12 - Prob. 3STPCh. 12 - Prob. 4STPCh. 12 - Prob. 5STPCh. 12 - Prob. 6STPCh. 12 - Prob. 7STPCh. 12 - Prob. 8STPCh. 12 - Prob. 9STPCh. 12 - Prob. 10STPCh. 12 - Prob. 11STPCh. 12 - Prob. 12STPCh. 12 - Prob. 13STPCh. 12 - Prob. 14STPCh. 12 - Prob. 15STPCh. 12 - Prob. 16STP

Additional Math Textbook Solutions

Find more solutions based on key concepts
Fill in each blanks so that the resulting statement is true. Any set of ordered pairs is called a/an _______. T...

College Algebra (7th Edition)

Compute the quantities in Exercises 18 using the vectors u = [12], v = [46], w = [315], x = [623] 1. uu, vu, an...

Linear Algebra and Its Applications (5th Edition)

NUMERIC For the following exercises, simplify the given expression. 34323 + 163

College Algebra

Fill in each blanks so that the resulting statement is true. Any set of ordered pairs is called a/an _______. T...

College Algebra

In the following exercise, name each number in words. 22.The height of Mount Adams is 12,276feet.

PREALGEBRA

In the following exercises, complete the square to make a perfect square trinomial. Then, write the result as a...

Elementary Algebra

Knowledge Booster
Background pattern image
Algebra
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, algebra and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Text book image
Algebra and Trigonometry (6th Edition)
Algebra
ISBN:9780134463216
Author:Robert F. Blitzer
Publisher:PEARSON
Text book image
Contemporary Abstract Algebra
Algebra
ISBN:9781305657960
Author:Joseph Gallian
Publisher:Cengage Learning
Text book image
Linear Algebra: A Modern Introduction
Algebra
ISBN:9781285463247
Author:David Poole
Publisher:Cengage Learning
Text book image
Algebra And Trigonometry (11th Edition)
Algebra
ISBN:9780135163078
Author:Michael Sullivan
Publisher:PEARSON
Text book image
Introduction to Linear Algebra, Fifth Edition
Algebra
ISBN:9780980232776
Author:Gilbert Strang
Publisher:Wellesley-Cambridge Press
Text book image
College Algebra (Collegiate Math)
Algebra
ISBN:9780077836344
Author:Julie Miller, Donna Gerken
Publisher:McGraw-Hill Education
SEE MORE TEXTBOOKS
The Shape of Data: Distributions: Crash Course Statistics #7; Author: CrashCourse;https://www.youtube.com/watch?v=bPFNxD3Yg6U;License: Standard YouTube License, CC-BY
Shape, Center, and Spread - Module 20.2 (Part 1); Author: Mrmathblog;https://www.youtube.com/watch?v=COaid7O_Gag;License: Standard YouTube License, CC-BY
Shape, Center and Spread; Author: Emily Murdock;https://www.youtube.com/watch?v=_YyW0DSCzpM;License: Standard Youtube License