Grade 7 Statistics

1. STATISTICS AND
PROBABILITY
Mathematics 7
Quarter 4

3. WHAT IS STATISTICS?
Statistics is the science of
Collecting
Organizing
Interpreting
and Analyzing data.
It is very important because it has many
applications in the society.

5. WHAT IS STATISTICS?
Statisticians, people who do statistics, are
particularly concerned with determining how to draw
reliable conclusions about large groups and general
events from the behavior and other observable
characteristics of small samples. These small
samples represent a portion of the large group or a
limited number of instances of a general
phenomenon.

7. What are the uses of
STATISTICS?
Statistics aids in decision making. This
includes the following purposes.
1. It allows comparison of quantities
2. It provides estimation of unknown quantities
3. It gives explanation to actions that has taken
place

8. WHAT IS DATA?
Data are units
of information,
often numeric,
recorded and used
for the purpose of
analysis.

9. WHAT IS DATA?

10. HOW CAN
STATISTICS SOLVE
PROBLEMS?

11. Situation 1: Academic Performance
Luisito, a grade 7 student would like
to know if his academic performance
improved from 1st quarter to 2nd quarter.
He decided to ask his adviser to show him
his report card. Based on the data on the
report card,
1. Did Luisito perform with improvement in
the second quarter?
2. What data on the report card will prove
that Luisito performed better?
3. What is the purpose of the grade
average?

12. Situation1: AcademicPerformance
Luisito, a grade 7 student would like to know if his
academic performance improved from 1st quarter to 2nd
quarter. He decided to ask his adviser to show him his
reportcard. Based on thedata on thereportcard,
1. Did Luisito perform with improvement in the second
quarter?
2. What data on the report card will prove that Luisito
performedbetter?
3. What is the purposeof the grade average?
Grade average serves as the numerical
equivalent of your TOTAL performance for the quarter. In
this case, Luisito got 87% in the second quarter which is
higher than that of the 1st quarter grade average of 85%.
This means Luisito performed better in the second
quarter.

13. Situation 2: Weather Reports
Melinda and her high school friends will
attend a 3-day field trip to Manila. As they are
planning for the trip, Melinda would like to
know if the weather will be fair for the next 3
days. She decided to watch the local weather
news. Based on the weather report,
1. If the 3-day trip will start on Friday, how will
you describe the upcoming weather?
2. What does 40% chance of precipitation for
the next 3 days mean?
3. Is it important to know the weather
conditions during outdoor activities?

14. Situation 2: Weather Reports
Melinda and her high school friends will attend a 3-day field
trip to Manila. As they are planning for the trip, Melinda would like to
know if the weather will be fair for the next 3 days. She decided to
watch the local weather news. Based on the weather report,
1. If the 3-day trip will start on Friday, how will you describe the
upcoming weather?
2. What does 40% chance of precipitation for the next 3 days mean?
3. Is it important to know the weather conditions during outdoor
activities?
Chance of precipitation is a data that is important in
weather reports. It is expressed in percent. A 40% chance of rain
means that there is a relatively average possibility that there will be
rain showers for the next 3 days. With these data, Melinda may
decide if she needs to bring an umbrella or raincoat or she may
decide to cancel the trip since it will possibly be rainy outside and
they may not be able to enjoy the outdoor viewing.

15. Situation 3: Exchange Rates
Mrs. Flores has just claimed a remittance from her
bank account amounting to 100 US dollars. She would
like to convert the money to pesos. The following
exchange rates were posted in front of her bank and
the other is in a money-exchange office. Based on the
data,
1. Which will Mrs. Flores choose, the rate offered by
the bank or the money changer? Why?
2. If the money changer is located a ride away that will
cost her to spend P150, will it still be a better decision
to convert the money to the money changer?
3. Is it important that you compare the exchange rates
of money changers?

16. Situation 3: Exchange Rates
Mrs. Flores has just claimed a remittance from her bank account amounting to 100 US
dollars. She would like to convert the money to pesos. The following exchange rates were
posted in front of her bank and the other is in a money-exchange office. Based on the data,
1. Which will Mrs. Flores choose, the rate offered by the bank or the money changer? Why?
2. If the money changer is located a ride away that will cost her to spend P150, will it still be a
better decision to convert the money to the money changer?
3. Is it important that you compare the exchange rates of money changers?
If Mrs. Flores will convert the money to the bank, the equivalent amount will be $100 x
P48.50 = Php4,850. If she visits the money changer, the amount will be $100xP49.50 = PhP4950,
which is P100 MORE THAN the bank’s offer. Thus, Mrs Flores should choose the money changer.
But if she will spend P150 in visiting the money changer, the better decision is to
convert her money in the bank. In converting foreign currency bills, it is important to canvass
first what are the available exchange rates near your place. Also, consider other expenses
such as transportation allowance, possible transaction fees and others.

17. Functions or Uses of
Statistics
Statistics helps in providing a better understanding and exact
description of a phenomenon of nature.
Statistics helps in proper and efficient planning of a statistical
inquiry in any field of study.
Statistics helps in collecting appropriate quantitative data.
Statistics helps in presenting complex data in a suitable tabular
and graphic form for an easy and clear comprehension of the
data.
Statistics helps in drawing valid inferences, along with a
measure of their reliability about the population parameters
from the sample data.

18. HOW CAN WE GET
THE NEEDED DATA?

19. Statistical
Instrument
This is a tool that researchers use to collect needed
data. Examples of instruments are survey questionnaires.

21. NOTE: Your survey questionnaire should have the 3 main parts.
Introduction – This gives the respondent the SURVEY TOPIC (or
what the survey is all about) and what to do with the survey.
Profile of Respondent – This Part I of the survey asks the
respondent certain important personal details. Some of which
can be optional, that is, the respondent is allowed not to give that
particular information such as Name.
Questions to answer – This Part II is the list of question items
which can be open-ended questions like nos. 1 and 2 or with
check boxes like no. 3.

22. ASSIGNMENT
Create a sample statistical instrument followingthe pointers
in the previous slides. On the A4 paper, write the SURVEY
TOPIC first, followed by the statistical instrument. Write at
least 5 questions (closed – ended or open – ended).
NOTE:Thequestions shouldbe RELEVANTandshouldaskfor
informationthat willanswerthe SURVEYTOPIC, or let us say,
questionsshouldbe coherentto the SurveyTopic.