Data handling: Class 7 maths video

0:00 Class 7 maths. Data handling.

0:03 Welcome to the Data Control Room!

0:06 Captain Calc needs your help to organize superhero test scores and predict upcoming mission outcomes.

0:13 Mean and Range of Data.

0:16 Data is a collection of numbers gathered to give information.

0:20 The arithmetic mean is calculated by dividing the sum of all values by the total number of values.

0:27 Try this one. Find the mean and range of Rohan's test marks: 40, 50, 30, 60, 70.

0:37 Sum of values = 40 + 50 + 30 + 60 + 70 = 250.

0:45 Total number of marks = 5.

0:48 Mean = 250 ÷ 5 = 50.

0:53 Highest value = 70 and Lowest value = 30. Range = 70 - 30 = 40.

1:02 So the answer is Mean = 50, Range = 40.

1:07 Mode of Data.

1:09 The mode is the value that appears most frequently in a dataset.

1:14 A dataset can have one mode, more than one mode, or no mode if all values appear equally.

1:20 Try this one. Find the mode of the numbers: 2, 4, 3, 2, 5, 2, 4.

1:27 Arrange in order: 2, 2, 2, 3, 4, 4, 5.

1:32 Count frequency: 2 appears 3 times, 4 appears 2 times, 3 and 5 appear once.

1:38 The number 2 has the highest frequency.

1:42 So the answer is 2.

1:44 Median of Data.

1:46 The median is the middle value when data is arranged in increasing or decreasing order.

1:53 It divides the given dataset into two equal halves.

1:57 Try this one. Find the median of the numbers: 7, 3, 9, 1, 5.

2:04 Arrange in ascending order: 1, 3, 5, 7, 9.

2:09 There are 5 numbers (odd count).

2:12 The middle position is (5 + 1) ÷ 2 = 3rd number.

2:17 The 3rd number is 5.

2:20 So the answer is 5.

2:22 Chance and Probability.

2:24 Probability measures how likely an event is to happen.

2:28 Probability of an event = (Number of favourable outcomes) ÷ (Total number of possible outcomes).

2:37 Try this one. A standard six-sided die is rolled once. What is the probability of getting a 4?

2:45 Total possible outcomes = 6 (numbers 1, 2, 3, 4, 5, 6).

2:51 Number of outcomes showing 4 = 1.

2:55 Probability = 1 ÷ 6 = 1/6.

2:60 So the answer is 1/6.

3:03 Your turn. The mean of 5 numbers is 12. What is the sum of the numbers? Pause the video, and try it.

3:12 The answer is 60.

3:15 Well done! Now try the practice and the quiz in this lesson on LearnFun.