Find probabilities for the standard normal distribution, Mathematics

Assignment Help:

Q. Find Probabilities for the Standard Normal Distribution?

Ans.

Suppose the history teacher decides to distribute the final grades of his class with a normal distribution. He wants to give a score of C or higher to all students who score within 1.1 standard deviations of the mean. What percentage of students will receive a mark of C or greater?

Solution:

463_standard deviations.gif


Use the table of probabilities for the normal standard distribution. The table shows that . This means that 86.43% of students have a z-score less than 1.1.

789_standard deviations1.gif


We know that 50% of the students scored below the mean. Thus, 86.43% or 50% = 36.43% of the students scored between the mean and 1.1 standard deviations above it.

Since the normal distribution is symmetric, there is also 36.43% of students which scored between a z-score of 1.3 and the mean.

The total percentage of students within 1.1 standard deviations of the mean is .

Thus 72.86% of the students in the history class will get a final mark of C or higher.


Related Discussions:- Find probabilities for the standard normal distribution

Show that a, If the roots of the equation (b-c)x 2 +(c-a)x +(a-b) = 0 are ...

If the roots of the equation (b-c)x 2 +(c-a)x +(a-b) = 0 are equal show that a, b, c are in AP. Ans:    Refer sum No.12 of Q.E. If (b-c)x 2 + (c-a) x + (a-b) x have equ

Find the are length and sketch the level curves, 1) Find the are length of ...

1) Find the are length of r(t) = ( 1/2t^2, 1/3t^3, 1/3t^3) where t is between 1 and 3 (greater than or equal less than or equal) 2) Sketch the level curves of f(x,y) = x^2-2y^2

What is the integratin of 1/sin2x?, ∫1/sin2x dx = ∫cosec2x dx = 1/2 log[cos...

∫1/sin2x dx = ∫cosec2x dx = 1/2 log[cosec2x - cot2x] + c = 1/2 log[tan x] + c Detailed derivation of ∫cosec x dx = ∫cosec x(cosec x - cot x)/(cosec x - cot x) dx = ∫(cosec 2 x

Boeing Company and Ingredient Branding Strategies, . The Boeing Company ma...

. The Boeing Company makes a number of different types of aircraft for the commercial airline industry, e.g., the 727, 747, 757, 767, and 777 jet models. Is there any way for Boei

What is the cost of one adult ticket, The cost of a student ticket is $1 mo...

The cost of a student ticket is $1 more than half of an adult ticket. Six adults and four student tickets cost $28. What is the cost of one adult ticket? Let x = the cost of a

Theory of equations, If p,q,r are roots of x^3-3x^2+4x-7=0 (p+2)(q+2)(...

If p,q,r are roots of x^3-3x^2+4x-7=0 (p+2)(q+2)(r+2)=

Diffrentiation, y=f(a^x)   and f(sinx)=lnx find dy/dx Solution) dy/dx...

y=f(a^x)   and f(sinx)=lnx find dy/dx Solution) dy/dx = (a^x)(lnx)f''(a^x), .........(1) but f(sinx) = lnx implies f(x) = ln(arcsinx) hence f''(x) = (1/arcsinx) (1/ ( ( 1-x

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd