Maharashtra Board Class 9 Maths Chapter 7 Set 7.1 Algebra Standard Part 1 Statistics Solutions

Question 1. The following table shows the number of Buses and Trucks in nearest lakh units. Draw percentage bar diagram. (Approximate the percentages to the nearest integer)

Answer:

ℹ️ चित्र व्याख्या (Diagram Explanation): यह एक प्रतिशत बार आरेख है जो 2005-2006 से 2009-2010 तक ट्रकों और बसों की संख्या को दर्शाता है। प्रत्येक वर्ष के लिए, कुल यातायात को 100% पर एक बार के रूप में दिखाया गया है, और फिर बसों और ट्रकों के संबंधित प्रतिशत को अलग-अलग रंगों से उप-विभाजित किया गया है। Y-अक्ष प्रतिशत दिखाता है जबकि X-अक्ष वर्ष दिखाता है।
In simple words: The solution involves calculating the percentage of trucks and buses for each year from their given numbers and then plotting these percentages as a percentage bar diagram, where each year's bar represents 100% of the total vehicles.

🎯 Exam Tip: Ensure accurate calculation of percentages and correct scaling of the Y-axis (1cm = 10%) when drawing percentage bar diagrams. Labeling the diagram clearly with 'Trucks' and 'Buses' is crucial for full marks.

Question 2. In the table given below, the information is given about roads. Using this draw sub-divided and percentage bar diagram (Approximate the percentages to the nearest integer)

Answer:
(i) Sub-divided bar diagram:

ℹ️ चित्र व्याख्या (Diagram Explanation): यह एक उप-विभाजित बार आरेख है जो 2000-2001 से 2007-2008 तक स्थायी और अस्थायी सड़कों की लंबाई को दर्शाता है। प्रत्येक वर्ष के लिए, एक बार कुल सड़कों की लंबाई का प्रतिनिधित्व करता है, जिसे स्थायी सड़कों (नीचे का खंड) और अस्थायी सड़कों (ऊपर का खंड) में उप-विभाजित किया गया है। Y-अक्ष सड़कों की लंबाई (लाख किमी में) दिखाता है जबकि X-अक्ष वर्ष दिखाता है।
(ii) Percentage bar diagram:

ℹ️ चित्र व्याख्या (Diagram Explanation): यह एक प्रतिशत बार आरेख है जो 2000-2001 से 2007-2008 तक स्थायी और अस्थायी सड़कों की लंबाई के प्रतिशत को दर्शाता है। प्रत्येक वर्ष के लिए, कुल सड़कों को 100% बार के रूप में दिखाया गया है, और फिर स्थायी और अस्थायी सड़कों के प्रतिशत को अलग-अलग रंगों से दर्शाया गया है। Y-अक्ष प्रतिशत दिखाता है जबकि X-अक्ष वर्ष दिखाता है।
In simple words: The solution requires creating two types of bar diagrams: a sub-divided bar diagram showing the actual lengths of permanent and temporary roads, and a percentage bar diagram showing their relative proportions (percentages) for each given year.

🎯 Exam Tip: For sub-divided diagrams, ensure the total length for each year is correctly plotted, and the segments for permanent and temporary roads are clearly marked. For percentage diagrams, all bars should reach 100%, with each segment representing its calculated percentage. Always include a clear scale and legend.

Maharashtra Board Class 9 Maths Chapter 7 Statistics Practice Set 7.1 Intext Questions and Activities

Question 1. A farmer has produced Wheat and Jowar in his field. The following joint bar diagram shows the production of Wheat and Jowar. From the gken diagram answer the following questions: (Textbook pg. no. 108)
(i) Which crop production has increased consistently in 3 years?
(ii) By how many quintals the production ofjowar has reduced in 2012 as compared to 2011?
(iii) What is the difference between the production of wheat in 2010 and 2012 ?
(iv) Complete the following table using this diagram.

ℹ️ चित्र व्याख्या (Diagram Explanation): यह एक संयुक्त बार आरेख है जो 2010, 2011 और 2012 के वर्षों में गेहूं और ज्वार के उत्पादन को क्विंटल में दर्शाता है। प्रत्येक वर्ष के लिए, दो अलग-अलग बार दिए गए हैं: एक गेहूं के उत्पादन के लिए और दूसरा ज्वार के उत्पादन के लिए। Y-अक्ष उत्पादन को क्विंटल में दिखाता है जबकि X-अक्ष वर्ष दर्शाता है।
Answer:
(i) The crop production of wheat has increased consistently in 3 years.
(ii) The production of jowar has reduced by 3 quintals in 2012 as compared to 2011.
(iii) The difference between the production of wheat in 2010 and 2012 = \(48 - 30 = 18\) quintals
(iv)

In simple words: By analyzing the given joint bar diagram, we can determine which crop's production shows a consistent increase, calculate the reduction in jowar production between specific years, find the difference in wheat production between two years, and complete a table with the production data.

🎯 Exam Tip: Carefully read the values from the bar diagram for each category (wheat and jowar) and each year. Pay attention to the labels on both axes and the scale to avoid reading errors. Ensure calculations for differences and table completion are accurate.

Question 2. In the following table, the information of number of girls per 1000 boys is given for different states. Fill In the blanks and complete the table. (Textbook pg. no. 111)

Answer: Draw percentage bar diagram from this information and discuss the findings from the diagram.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह एक प्रतिशत बार आरेख है जो विभिन्न राज्यों में प्रति 1000 लड़कों पर लड़कियों की संख्या के आधार पर लड़कों और लड़कियों के प्रतिशत को दर्शाता है। प्रत्येक राज्य के लिए, कुल जनसंख्या (लड़के + लड़कियां) को 100% पर एक बार के रूप में दिखाया गया है, जिसे लड़कों और लड़कियों के प्रतिशत में विभाजित किया गया है। Y-अक्ष प्रतिशत दिखाता है जबकि X-अक्ष राज्य दिखाता है।
In simple words: We complete the table by calculating the total population (boys + girls) and then determining the percentage of boys and girls for each state, approximating to the nearest integer. Then, a percentage bar diagram is drawn based on these calculated percentages.

🎯 Exam Tip: Ensure all percentage calculations are correct and rounded to the nearest integer as specified. When drawing the percentage bar diagram, each bar must represent 100% of the total, with appropriate segments for boys and girls clearly labeled. A clear scale (1cm = 10%) on the Y-axis and state names on the X-axis are essential.

Question 3. For the above given activity, the information of number of girls per 1000 boys is given for five states. The literacy percentage of these five states is given below. Assam (73%), Bihar (64%), Punjab (77%), Kerala (94%), Maharashtra (83%). Think of the number of girls and the literacy percentages in the respective states. Can you draw any conclusions from it? (Textbook pg. no. 112)
Answer: By observing the number of girls per 1000 boys and literacy percentages in the given respective states, we can conclude that the literacy rate of girls is least in Bihar and is highest in Kerala.
In simple words: By comparing the ratio of girls to boys with the literacy rates in different states, we can observe a correlation, specifically noting that states with higher female literacy rates tend to have a more balanced sex ratio.

🎯 Exam Tip: When drawing conclusions, connect the data points logically. Here, the conclusion links the sex ratio (number of girls per 1000 boys) to the literacy rate, highlighting states with extremes in both categories.