## Normal Distribution on the TI89 using Statistics Made Easy

ex1. What is the probability of obtaining a sample mean greater than M=60 for a random sample of n=16 scores selected from a normal population with a mean of 65 and a standard deviation of 20?

Go To F3 7 and select Normal distribution, enter
mu=65
std dev=20/sqrt(16)=20/4 = 5 so just enter 5
M = 60

Then in the dropdown menu select option 2: P(x>a) . Voila 84.1345%

ex2. What are the boundaries for the middle 50% of all possible random samples of n=25 scores selected from a normal population with a mean of 80 and a standard deviation of 10?

Go To F3 7 , enter
mu=80
std dev=10/sqrt(25)=10/5 = 2 so just enter 2
and in the dropdown menu select 6 NormInverse :
enter .25 (for the left 50% bound)
next redo above and enter .75 to the upper right bound.

Also, is there any way to use SPME to obtain or calculate values found in Statistical unit normal tables?

Sure, F3 7 . Use mu=1 and Std Dev=0 and a and b is desired , then use options 1, 2, 3 in the dropdown menu.

## Linear Algebra and Chemistry apps for the TI-Nspire CX available at www.TiNspireApps.com

Great News:

As usual , Step by Step solutions to Linear Algebra, Matrix and Vector problems as well as

Visit www.TiNspireApps.com for more details.

## New Ti-Nspire apps available: Chemistry and Differential Equations

1) Step by Step Chemistry solutions for Stoichiometry, Mass, Moles, Gas Laws , Period Table of Elements, Significant Digits and much more.

2) Step by Step Differential Equation solutions: 1. , 2. and higher order Differential Equations, Laplace and Inverse Transforms and much more

Questions: support@TiNspreApps.com

## Solving 2. order Vibrating Spring Differential Equation using the TI89

The shown spring problem can be solved using DEQME : F2 G enter

w=9.81 (to make coeff=1)

g=9.81

b=0

k=64

F=0

Hit ENTER about 7 times , Variation of Parameter will be used to solve, then you may enter your initial conditions

x0=0

y(x0)=2/3

y'(x0)=-4/3

Voila!!

## Solve 2. and 3. order Differential Equations using TI89

Using Differential Equations Made for the TI89 we enter the 3 problems as shown below. Screenshots show how the problems were entered and the solutions.

Question 2) y”-2y+5y=0   y(0)=2  y'(0)=4

go to F2 2 and enter b=-2 and c=5 , x0=0, y(x0)=2 y,(x0)=4

Question 3) y”-3y+2y=6e^(-x)    y(0)=1 y'(0)=2 .

go to F2 3 and enter b=-3 c=2 , g=6e^(-x) x0=0 y(x0)=1 y'(x0)=2 . The corresponding homogeneous solution can be found with steps under F2 2

Question 4)  y”’-4y”+13y’=e^(-x)

the solution is the sum of the homogeneous and particular solutions. Thus, use 2 steps.

first find the homogeneous solution under F3 1 and enter t^3-4t^2+13t=0

next F3 2 . a=-4 b=13 c=0 g=e^(-x) to find part. solution -1/18 e^(-x)

## Algebra Made Easy for TI-Nspire CX CAS is now available at www.TiNspireapps.com

Algebra Made Easy for TI-Nspire CX CAS is now available at www.TiNspireapps.com
showing Step by Step solutions to all PreCalculus topics :
-Step by Step Algebra
-Step by Step Functions
-Step by Step Sequences & Series
-Step by Step Polynomials
-Step by Step Exponential and Logarithmic functions
-Step by Step Matrices & Vectors
-Step by Step Quadratic Equations and Complex Numbers
-Step by Step Trigonometry

The Algebra App requires a CAS Nspire CX. Check on the top right of your TI Nspire CX for the letters CAS.

It is small in size (33kb) considering the large memory the TiNspire CX offers.

Questions: support

## PreCalculus Made Easy for TI-Nspire CX CAS is now available at www.TiNspireapps.com

PreCalculus Made Easy for TI-Nspire CX CAS is now available at www.TiNspireapps.com
showing Step by Step solutions to all PreCalculus topics :
-Step by Step Algebra
-Step by Step Functions
-Step by Step Sequences
-Step by Step Polynomials
-Step by Step Exponential and Logarithmic functions
-Step by Step Matrices & Vectors
-Step by Step Conic Functions
-Step by Step Quadratic Equations and Complex Numbers
-Step by Step Trigonometry
-Step by Step Intro to Calculus

The Precalculus App requires a CAS Nspire CX. Check on the top right of your TI Nspire CX for the letters CAS.

It is small in size (33kb) considering the large memory the TiNspire CX offers.

Questions: support

## Calculus Made Easy for TI-Nspire CX CAS available at www.tinspireapps.com

Calculus Made Easy for TI-Nspire CX CAS is now available at www.TiNspireapps.com
showing Step by Step solutions to all Calculus I,II, III topics :
-Step by Step Differentiation
-Step by Step Integration
-Step by Step Differential Equations
-Step by Step Parametric Equations
-Step by Step Polar Functions
-Step by Step Multivariable Calculus
-Step by Step Limits and L’Hopital Rule
-Step by Step Implicit Differentiation

Trial is available.

The Calculus App requires a CAS Nspire CX. Check on the top right of your TI Nspire CX for the letters CAS.

It is fairly small in size (55kb) considering the large memory the TiNspire CX offers.

Questions: support