Periodic Functions

To get the squiggly line, sin, cos, or tan(x)
Periodic function- One which repeats regularly over the same number of independant variable units (Domain), predictably.
In your calculator, when setting sin(x) always use zoom 7.
y=a. sin(bx+c)+d
Sinusoidal function - squiggly wave
"a"- value - controls the AMPLITUDE of the function. When measuring AMPLITUDE -
(max-min)/2
"b" value - controls the PERIOD of the function - b=(2pi)/period OR period= (2pi)/b
"c" value - controls the PHASE SHIFT or HORIZONTAL SHIFT - Left and right only
phase shift = -c/b
"d" value - controls the VERTICAL SHIFT - Up and down only

Z-scores

Z-score formula:
Z= (x-xbar)
---------
ox
" the z score measures the distance plus or minus from the mean in units of std deviation"
x- what you got
xbar- what they got
ox- std deviation
if number is negative its BAD, positive, GOOD!
TO CLR LIST 2nd + 4 ENTER

Characteristics of normal distribution:

Characteristics of normal distribution:
Theoretical (aproximation)
Symmetry about mean
Follows this rule:
68-95-99.7
mean-median-mode
2nd vars gets you to Normal cdf (low value, high value, x, ox)
How do you find out how many fish longer than 40 cm?
Normal cdf(40, E99)
E=2nd --> ,

Boundaries, grouped data

Once you have your grouped data, enter it into your calculator in your lists and then
STAT--> CALC--> 1-var stats--> L2, L2

Mean Median and Mode.
Mean - avg
Median - middle number
mode - happens most
To get std deviation - stat -> calc -> 1-var stats
x-mean
Ex-sum of all numbers
Ex2- sum of all numbers squared
sx- DONT USE
ax- USE! std. dev.
std dev, no spread - 0
big spread, high

Schedule of payments

Today we are using excel to make a schedule of payments. In don want to blog too much because i have to listen it is going by pretty fast and i need to pay attention. Untill we meet again!

To add a payment function - Formulas->insert function->PMT

Whoah! havent blogged in a while! today we are learning about tvm
n=number of times in total interest is compounded.
APPS ENTER ENTER
i%=interest rate as A.P.R.
PV= Present value(value at time now)
PMT=Payment per period
FV= Future value
P/Y= Payments per year
C/Y= compoundings per year