STATISTICS
and
PROBABILITY
MRS. JONNAH MARIZ NACAR-BERNAL
M AT H E M AT I C S 1 1
KEEP QUIET WHEN
SOMEONE IS TALKING
CLA SS RU LE
CLA SS RU LE
RAISE HAND IF YOU
WANT TO SHARE SOME
IDEAS
NO USING OF
CELLPHONES
CLA SS RU LE
Q UI CK REV I EW
PROPERTIES OF A
NORMAL DISTRIBUTION
PROPERTIES OF A
NORMAL DISTRIBUTION
SHORT
EXERCISE
Yes or
No
Game
stats and prob edition
The
Rules
•Answer the
questions within 10
second
•If the answer is
correct the GROUP
will get 1 point
•if the answer is wrong
the GROUP will lose 1
point
•Have fun!
The expression 68% is the
same as 0.68
The Question
You have 10 seconds
Yes
The
Answer
a probability value is a
number from 0 to 1
The Question
You have 10 seconds
Yes
The
Answer
the scores at the base
line of the normal curve
are called x
The
Question
You have 10 seconds
No
The
Answer
z - values
the normal curve is
a probability
distribution
The
Question
You have 10 seconds
Yes
The
Answer
the normal curve is
asymmetrical
The
Question
You have 10 seconds
No
The
Answer
it is symmetrical
Good Job
Everyone!!
Random Variables
And
Probability
Distribution
S T A T I S T I C S
a n d
P R O B A B I L I T Y
LEA RN IN G
O BJE CTI V ES
a.Identify regions under the normal curve
corresponding to the different standard
normal values;
b.Find the area under the normal curve either to
the right or left of the given standard normal
value; and
c.Perform finding the area under the normal
curve with accuracy and patience
M A T H E M A T I C S
1 1
Figure A
= 45
= 6
Figure B
= 0
= 1
M A T H E M A T I C S
1 1
Figure 1 has a raw values, not standardized while
figure 2 is in standardized normal distribution
values
CONCLUSION
- A random variable that has a normal distribution with
a mean of zero and a standard deviation of one.
- The letter z is commonly used to designate the normal
random variable.
S t a n d a r d N o r m a l
D i s t r i b u t i o n
W h y d o w e n e e d t o
s t a n d a r d i z e d t h e v a l u e s ?
- A normal variable is standardized to simplify the
process in approximating areas for normal curves.
- a table was created to summarize the areas under the
standard normal curve and to further simplify the
process. This table of probabilities is known as the z-
table.
S t a n d a r d N o r m a l
D i s t r i b u t i o n
S t a n d a r d N o r m a l
D i s t r i b u t i o n
- The intersection of the
columns and rows that
contain the digits of the
scores
- A cell that has a total area
from the left end of the
normal curve to the z-scores
Z - t a b l e
-3 -2 -1 0 1 2 3
1. shade the area
between 1 and 2.
2. Shade the area
between -1 and -3
3. Area between 0
and 2
Task
The z-table provides the section of the
area between any two specific values
under the curve, regions under the curve
can be described in terms of area.
Z - t a b l e
How t o u s e t h e z -
t ab l e
Find the area that corresponds to z =
1.85.
EX AM P LE
Find the area that corresponds to z =
1.85.
STEP
S
1. LOCATE the first two digits in the leftmost
column
2. The last digit is found at the first row of the
table
3. Find their intersection which gives the
corresponding area from the mean
Find the area that corresponds to z =
1.85
1. LOCATE the first two digits in the leftmost
column
2. The last digit is found at the first row of the
table
Find the area that corresponds to z =
1.85
3. Find their intersection which gives the
corresponding area from the mean
This means that the area of the z score of 1.85 from
the mean is 0.46784 or 46.78%.
Find the area that corresponds to z = 2.67, can someone
answer?
This means that the area of the z score of 1.85 from
the mean is 0.49621 or 49.62%.
Determine the area under the standard normal
curve to the right of 1.63.
STEPS
0.5 – 0.44845 =
0.05155 or 5.15%
ANSWER
Determine the area under the standard normal
curve to the right of 1.63.
Determine the area under the standard normal
curve to the right of -0.67.
STEPS
0.5 + 0.24857 =
0.77935 or 77.94%
ANSWER
Determine the area under the standard normal
curve to the right of -0.67.
C O N V E R T I N G T H E V A L U E O F X
I N T O Z - S C O R E S
Given a normal random variable X with mean (µ) and
standard deviation ( ), each value of x of the
𝜎
variable can be transformed into z-scores using the
formula
A random variable X has a mean of 6
and a standard deviation of 2. Find the
corresponding z- score for x = 11.
EX AM P LE
ANSWER
z = 2.5
A random variable X has a mean of 6
and a standard deviation of 2. Find the
corresponding z- score for x = 11.
EX AM P LE
A random variable X has a mean of
28 and a standard deviation of 5. Find
the corresponding z- score for x = 18.
EX AM P LE
ANSWER
z = -2
0.47725 or 47.73%
Let x be a normally distributed random
variable with a mean of 10 and a standard
deviation of 2. Find the probability that x
lies between 11 and 13.6.
EX AM P LE
ANSWER
z = 1.3
0.40320 or 40.32%
Directions: complete the given diagram
below by filling up the necessary details
about the steps in finding the probability
using the standard normal curve and
finding the z - scores
AC T I V I T Y
Work by pairs
Directions: complete the given diagram below by filling up the necessary details
about the steps in finding the probability using the standard normal curve and
finding the z - scores
EN D O F T HE LE SSO N

Demonstration Teaching in Mathematics 11

  • 1.
    STATISTICS and PROBABILITY MRS. JONNAH MARIZNACAR-BERNAL M AT H E M AT I C S 1 1
  • 2.
    KEEP QUIET WHEN SOMEONEIS TALKING CLA SS RU LE
  • 3.
    CLA SS RULE RAISE HAND IF YOU WANT TO SHARE SOME IDEAS
  • 4.
  • 5.
    Q UI CKREV I EW PROPERTIES OF A NORMAL DISTRIBUTION
  • 6.
  • 7.
  • 8.
  • 9.
    The Rules •Answer the questions within10 second •If the answer is correct the GROUP will get 1 point •if the answer is wrong the GROUP will lose 1 point •Have fun!
  • 10.
    The expression 68%is the same as 0.68 The Question You have 10 seconds
  • 11.
  • 12.
    a probability valueis a number from 0 to 1 The Question You have 10 seconds
  • 13.
  • 14.
    the scores atthe base line of the normal curve are called x The Question You have 10 seconds
  • 15.
  • 16.
    the normal curveis a probability distribution The Question You have 10 seconds
  • 17.
  • 18.
    the normal curveis asymmetrical The Question You have 10 seconds
  • 19.
  • 20.
  • 21.
    Random Variables And Probability Distribution S TA T I S T I C S a n d P R O B A B I L I T Y
  • 22.
    LEA RN ING O BJE CTI V ES a.Identify regions under the normal curve corresponding to the different standard normal values; b.Find the area under the normal curve either to the right or left of the given standard normal value; and c.Perform finding the area under the normal curve with accuracy and patience
  • 23.
    M A TH E M A T I C S 1 1 Figure A = 45 = 6 Figure B = 0 = 1
  • 24.
    M A TH E M A T I C S 1 1 Figure 1 has a raw values, not standardized while figure 2 is in standardized normal distribution values CONCLUSION
  • 25.
    - A randomvariable that has a normal distribution with a mean of zero and a standard deviation of one. - The letter z is commonly used to designate the normal random variable. S t a n d a r d N o r m a l D i s t r i b u t i o n
  • 26.
    W h yd o w e n e e d t o s t a n d a r d i z e d t h e v a l u e s ?
  • 27.
    - A normalvariable is standardized to simplify the process in approximating areas for normal curves. - a table was created to summarize the areas under the standard normal curve and to further simplify the process. This table of probabilities is known as the z- table. S t a n d a r d N o r m a l D i s t r i b u t i o n
  • 28.
    S t an d a r d N o r m a l D i s t r i b u t i o n
  • 29.
    - The intersectionof the columns and rows that contain the digits of the scores - A cell that has a total area from the left end of the normal curve to the z-scores Z - t a b l e
  • 30.
    -3 -2 -10 1 2 3 1. shade the area between 1 and 2. 2. Shade the area between -1 and -3 3. Area between 0 and 2 Task
  • 31.
    The z-table providesthe section of the area between any two specific values under the curve, regions under the curve can be described in terms of area. Z - t a b l e
  • 32.
    How t ou s e t h e z - t ab l e
  • 33.
    Find the areathat corresponds to z = 1.85. EX AM P LE
  • 34.
    Find the areathat corresponds to z = 1.85. STEP S 1. LOCATE the first two digits in the leftmost column 2. The last digit is found at the first row of the table 3. Find their intersection which gives the corresponding area from the mean
  • 35.
    Find the areathat corresponds to z = 1.85 1. LOCATE the first two digits in the leftmost column 2. The last digit is found at the first row of the table
  • 36.
    Find the areathat corresponds to z = 1.85 3. Find their intersection which gives the corresponding area from the mean This means that the area of the z score of 1.85 from the mean is 0.46784 or 46.78%.
  • 37.
    Find the areathat corresponds to z = 2.67, can someone answer? This means that the area of the z score of 1.85 from the mean is 0.49621 or 49.62%.
  • 38.
    Determine the areaunder the standard normal curve to the right of 1.63. STEPS
  • 39.
    0.5 – 0.44845= 0.05155 or 5.15% ANSWER Determine the area under the standard normal curve to the right of 1.63.
  • 40.
    Determine the areaunder the standard normal curve to the right of -0.67. STEPS
  • 41.
    0.5 + 0.24857= 0.77935 or 77.94% ANSWER Determine the area under the standard normal curve to the right of -0.67.
  • 42.
    C O NV E R T I N G T H E V A L U E O F X I N T O Z - S C O R E S
  • 43.
    Given a normalrandom variable X with mean (µ) and standard deviation ( ), each value of x of the 𝜎 variable can be transformed into z-scores using the formula
  • 44.
    A random variableX has a mean of 6 and a standard deviation of 2. Find the corresponding z- score for x = 11. EX AM P LE ANSWER z = 2.5
  • 45.
    A random variableX has a mean of 6 and a standard deviation of 2. Find the corresponding z- score for x = 11. EX AM P LE
  • 46.
    A random variableX has a mean of 28 and a standard deviation of 5. Find the corresponding z- score for x = 18. EX AM P LE ANSWER z = -2 0.47725 or 47.73%
  • 47.
    Let x bea normally distributed random variable with a mean of 10 and a standard deviation of 2. Find the probability that x lies between 11 and 13.6. EX AM P LE ANSWER z = 1.3 0.40320 or 40.32%
  • 48.
    Directions: complete thegiven diagram below by filling up the necessary details about the steps in finding the probability using the standard normal curve and finding the z - scores AC T I V I T Y Work by pairs
  • 49.
    Directions: complete thegiven diagram below by filling up the necessary details about the steps in finding the probability using the standard normal curve and finding the z - scores
  • 50.
    EN D OF T HE LE SSO N

Editor's Notes

  • #29 The z-table is divided into two sections, negative and positive z-scores. Negative z-scores are below the mean, while positive z-scores are above the mean. Row and column headers define the z-score while table cells represent the area.