
Concept explainers
a.
To calculate: The percent of light bulbs that will last for less than 900 hours.
a.

Answer to Problem 7WE
The percent of light bulbs that will last for less than 900 hoursis
Explanation of Solution
Given information:
900 hours is the mean life of a certain kind of light bulb with a standard deviation of 30 hours.
Formula used:
The number x is known as standardized value to z where z is provided value of
Calculation:
Consider the provided information that 900 hours is the mean life of a certain kind of light bulb with a standard deviation of 30 hours.
To compute percent of light bulbs that will last for less than 900 hours.
Recall that the number x is known as standardized value to z where z is provided value of normal distribution, m is the mean and
Here, z is 900, m is 900 and
Apply it,
The total area under the curve is 1 and standard normal curve is symmetric about y -axis.
The required percent is the area under the curve of standard normal to the left of
Multiply the result by 100, to obtain the answer in percentage form,
Thus, the percent of light bulbs that will last for less than 900 hours is
b.
To calculate: The percent of light bulbs that will last for more than 984 hours.
b.

Answer to Problem 7WE
The percent of light bulbs that will last for more than 984 hoursis
Explanation of Solution
Given information:
900 hours is the mean life of a certain kind of light bulb with a standard deviation of 30 hours.
Formula used:
The number x is known as standardized value to z where z is provided value of normal distribution, m is the mean and
Calculation:
Consider the provided information that 900 hours is the mean life of a certain kind of light bulb with a standard deviation of 30 hours.
To compute percent of light bulbs that will last for more than 984 hours.
Recall that the number x is known as standardized value to z where z is provided value of normal distribution, m is the mean and
Here, z is 984, m is 900 and
Apply it,
The total area under the curve is 1 and standard normal curve is symmetric about y -axis.
The required percent is the area under the curve of standard normal to the right of
Multiply the result by 100, to obtain the answer in percentage form,
Thus, the percent of light bulbs that will last for more than 984 hours is
Chapter 15 Solutions
Algebra and Trigonometry: Structure and Method, Book 2
Additional Math Textbook Solutions
Calculus: Early Transcendentals (2nd Edition)
University Calculus: Early Transcendentals (4th Edition)
Pre-Algebra Student Edition
Elementary Statistics (13th Edition)
A First Course in Probability (10th Edition)
- Safari File Edit View History Bookmarks Window Help Ο Ω OV O mA 0 mW ర Fri Apr 4 1 222 tv A F9 F10 DII 4 F6 F7 F8 7 29 8 00 W E R T Y U S D பட 9 O G H J K E F11 + 11 F12 O P } [arrow_forwardSo confused. Step by step instructions pleasearrow_forwardIn simplest terms, Sketch the graph of the parabola. Then, determine its equation. opens downward, vertex is (- 4, 7), passes through point (0, - 39)arrow_forward
- In simplest way, For each quadratic relation, find the zeros and the maximum or minimum. a) y = x 2 + 16 x + 39 b) y = 5 x2 - 50 x - 120arrow_forwardIn simplest terms and step by step Write each quadratic relation in standard form, then fi nd the zeros. y = - 4( x + 6)2 + 36arrow_forwardIn simplest terms and step by step For each quadratic relation, find the zeros and the maximum or minimum. 1) y = - 2 x2 - 28 x + 64 2) y = 6 x2 + 36 x - 42arrow_forward
- Write each relation in standard form a)y = 5(x + 10)2 + 7 b)y = 9(x - 8)2 - 4arrow_forwardIn simplest form and step by step Write the quadratic relation in standard form, then fi nd the zeros. y = 3(x - 1)2 - 147arrow_forwardStep by step instructions The path of a soccer ball can be modelled by the relation h = - 0.1 d 2 + 0.5 d + 0.6, where h is the ball’s height and d is the horizontal distance from the kicker. a) Find the zeros of the relation.arrow_forward
- Algebra and Trigonometry (6th Edition)AlgebraISBN:9780134463216Author:Robert F. BlitzerPublisher:PEARSONContemporary Abstract AlgebraAlgebraISBN:9781305657960Author:Joseph GallianPublisher:Cengage LearningLinear Algebra: A Modern IntroductionAlgebraISBN:9781285463247Author:David PoolePublisher:Cengage Learning
- Algebra And Trigonometry (11th Edition)AlgebraISBN:9780135163078Author:Michael SullivanPublisher:PEARSONIntroduction to Linear Algebra, Fifth EditionAlgebraISBN:9780980232776Author:Gilbert StrangPublisher:Wellesley-Cambridge PressCollege Algebra (Collegiate Math)AlgebraISBN:9780077836344Author:Julie Miller, Donna GerkenPublisher:McGraw-Hill Education





