Explore Chapter 11: Biostatistics from the 9th class new syllabus. Comprehensive guide for Lahore Board, all Punjab Boards, and Federal Board students, tailored to meet the updated syllabus requirements.
1. What is the primary purpose of biostatistics?
- Options:
a) To analyze financial data
b) To apply statistical methods to biological sciences
c) To design engineering models
d) To study historical events - Answer: b) To apply statistical methods to biological sciences
- Explanation:
Biostatistics is the branch of statistics that focuses on applying statistical methods to biological and medical research. - Tip:
Remember, “bio” refers to life sciences and “statistics” involves data analysis. Combine both for the purpose.
2. In biostatistics, which method is used to predict future outcomes based on current data?
- Options:
a) Designing experiments
b) Interpreting results
c) Predicting outcomes
d) Analyzing data - Answer: c) Predicting outcomes
- Explanation:
In biostatistics, prediction involves using models and analysis of current data to make future estimations, like disease trends. - Tip:
Focus on the keyword “future outcomes,” which points to prediction.
3. Which of the following best describes the mean of a data set?
- Options:
a) The most frequently occurring value
b) The middle value when data is ordered
c) The sum of all values divided by the number of values
d) The difference between the highest and lowest values - Answer: c) The sum of all values divided by the number of values
- Explanation:
The mean is calculated by adding all values and dividing by how many values there are. It’s often referred to as the “average.” - Tip:
Mean = Total Sum ÷ Number of Values. This formula always helps!
4. If the data set is 5, 8, 12, 15, 20, what is the median?
- Options:
a) 8
b) 12
c) 15
d) 20 - Answer: b) 12
- Explanation:
The median is the middle value when data is arranged in order. Here, 12 is the middle value. - Tip:
For odd-numbered data, directly find the middle number after sorting.
5. What is the mean of the data set: 7, 8, 9, 10, 11?
- Options:
a) 7
b) 8
c) 9
d) 10 - Answer: c) 9
- Explanation:
Mean = (7 + 8 + 9 + 10 + 11) ÷ 5 = 45 ÷ 5 = 9. - Tip:
Use the formula and divide step by step to avoid calculation mistakes.
6. When the number of values in a data set is even, how is the median calculated?
- Options:
a) By choosing the middle value
b) By taking the average of the two middle values
c) By selecting the most frequent value
d) By adding all values and dividing by the total number of values - Answer: b) By taking the average of the two middle values
- Explanation:
For an even number of values, there’s no single middle value. You take the average of the two central numbers. - Tip:
If there are two middle values, calculate their mean to get the median.
7. In a data set with values 3, 3, 6, 7, 8, 9, 9, what is the mode?
- Options:
a) 3
b) 9
c) Both 3 and 9
d) 7 - Answer: c) Both 3 and 9
- Explanation:
The mode is the value(s) that appear most frequently. Here, both 3 and 9 occur twice. - Tip:
A data set can have more than one mode (bimodal), or no mode at all if no number repeats.
8. If a data set has no repeated values, what is the mode?
- Options:
a) The highest value
b) The average of the data set
c) There is no mode
d) The median value - Answer: c) There is no mode
- Explanation:
The mode refers to the most frequent value. If no value repeats, there is no mode. - Tip:
When solving, check if any numbers are repeated. If none, the mode does not exist.
A. Select the correct answers
9. In a bar chart, what does the height or length of each bar represent?
- Options:
a) The total number of categories
b) The value of the corresponding category
c) The average of all values
d) The difference between the highest and lowest values - Answer: b) The value of the corresponding category
- Explanation:
The height or length of each bar in a bar chart shows the value of the specific category it represents. - Tip:
Look at the y-axis (vertical axis) for the values.
10. When constructing a bar chart, which axis usually represents the categories?
- Options:
a) Vertical axis (y-axis)
b) Horizontal axis (x-axis)
c) Both axes equally represent the categories
d) Neither axis represents the categories - Answer: b) Horizontal axis (x-axis)
- Explanation:
In a bar chart, the x-axis typically represents the categories (e.g., types of items), while the y-axis represents the values (e.g., quantities). - Tip:
Remember: categories = x-axis, values = y-axis.
B. Write short answers
1. Define biostatistics.
Biostatistics is the application of statistical methods to biological and medical research. It helps analyze data to make informed decisions in health and science.
2. What is the median of a data set?
The median is the middle value of a data set when arranged in ascending or descending order.
3. How is the mean calculated?
The mean is calculated by dividing the sum of all values by the total number of values. Formula:
Mean = (Sum of all values) ÷ (Number of values).
4. What does the height of a bar in a bar chart represent?
The height of a bar represents the value of the corresponding category in the data.
5. What is the mode of a data set?
The mode is the value that appears most frequently in a data set.
C. Write answers in detail
1. Explain the importance of biostatistics in the field of public health.
Biostatistics plays a vital role in public health by:
- Analyzing disease patterns to understand their spread and prevention.
- Guiding health policies and resource allocation.
- Evaluating the effectiveness of treatments and interventions through statistical studies.
- Helping in predicting future health trends based on current data.
Example: Tracking COVID-19 cases and designing vaccination strategies.
2. Discuss the differences between mean, median, and mode. Include examples where each measure is most appropriate to use.
- Mean: The average of all values. Used when data is evenly distributed.
Example: Average score of students in a test. - Median: The middle value in a sorted data set. Useful for skewed data.
Example: Median income in a neighborhood with varying incomes. - Mode: The most frequent value. Used in categorical data.
Example: The most sold product in a store.
3. Describe the steps involved in creating a bar chart using Excel. Include a discussion on how to customize the chart for better visualization.
Steps to create a bar chart in Excel:
- Enter data into two columns: categories and their values.
- Select the data and click on the “Insert” tab.
- Choose the “Bar Chart” option.
- Customize the chart:
- Add titles for the chart and axes.
- Adjust colors to improve readability.
- Add data labels to show exact values.
- Save or export the chart for use.
4. Provide a detailed example of how to calculate the mean, median, and mode of a data set.
Data set: 12, 22, 8, 19, 25, 15
- Mean:
Mean=12+22+8+19+25+156=1016=16.83\text{Mean} = \frac{12 + 22 + 8 + 19 + 25 + 15}{6} = \frac{101}{6} = 16.83 - Median:
Arrange in order: 8, 12, 15, 19, 22, 25.
The middle values are 15 and 19. Median = 15+192=17\frac{15 + 19}{2} = 17. - Mode:
No value repeats, so there is no mode.
5. You are given the following data set. Create a bar chart to represent the number of different types of fruits sold at a market in one week:
- Apples: 30
- Bananas: 45
- Oranges: 25
- Grapes: 20
To create the chart:
- List fruits and their numbers.
- Create a bar chart (using Excel or by hand) with fruits on the x-axis and their quantities on the y-axis.
- Label the chart with a title: “Fruits Sold in One Week.”
