1.
What is the ideal number of intervals for a set of data?
Correct Answer
D. Between 5 and 15
Explanation
The ideal number of intervals for a set of data is between 5 and 15. This range allows for a sufficient level of detail in the data without overwhelming the reader with too many intervals. Having fewer than 5 intervals may result in oversimplification and loss of important information, while having more than 15 intervals may make it difficult to interpret the data accurately. Therefore, a range of 5 to 15 intervals strikes a balance between providing enough detail and maintaining clarity.
2.
The number of intervals we choose for a data set is 'arbitrary'. What does this mean?
Correct Answer
C. Randomly chosen
Explanation
This means that the number of intervals selected for a data set is not predetermined or based on a specific formula or criteria. Instead, it is chosen without any specific pattern or rule, making it a random selection.
3.
The interval width we choose is designed to :
Correct Answer
B. Show a pattern in the data
Explanation
The interval width we choose is designed to show a pattern in the data. By selecting an appropriate interval width, we can group the data into meaningful categories or ranges, which allows us to identify any patterns or trends that may exist in the data. This helps in analyzing and interpreting the data more effectively, as it highlights any regularities or relationships that might be present.
4.
I have data from 200 people regarding their resting heart rates - from 47 beats per minute to 108 beats per minute. If I decide to make the intervals 10 wide, how many intervals would I have?
Correct Answer
7
Explanation
108 - 47 = 61 ... the range is 61. So, divide by 10, that gives you 6.1 - so it is likely to be 7, possibly 8. Test it.
Starting at 40-49.9, 50-, 60- 70-, 80-, 90-, 100-109.9
5.
I have data from 200 people regarding their resting heart rates - from 67 beats per minute to 108 beats per minute. If I decide to make the intervals 10 wide, how many intervals would I have?
Correct Answer
5
Explanation
108 - 67 = 41 ... the range is 41. So, divide by 10, that gives you 4.1 - so it is likely to be 5, possibly 6. Test it.
Starting at 60-60.9, 70-, 80-, 90-, 100-109.9
6.
What is the width of the interval class shown in the histogram above
Correct Answer
2
Explanation
The width of the interval class shown in the histogram is 2. This means that each interval in the histogram has a width of 2 units.
7.
The histogram below displays a set of data in interval classes. The first class goes from 76-77.9, the second from 78-79.9 etc.What is the modal class interval?
Correct Answer
82-83.9
Explanation
The modal class interval is the interval that has the highest frequency or the tallest bar in the histogram. In this case, the given histogram does not provide any information about the frequencies of the intervals. Therefore, it is not possible to determine the modal class interval based on the given information.
8.
What is the width of the interval class shown in the histogram above?
Correct Answer
1
Explanation
The width of the interval class shown in the histogram above is 1. This means that each interval in the histogram has a width of 1 unit.
9.
What is the frequency of the modal interval?
Correct Answer
5
10.
How many interval classes are in the histogram above?
Correct Answer
7
Explanation
The histogram above shows the distribution of data across different intervals. Each interval represents a range of values. By counting the number of intervals shown in the histogram, we can determine the number of interval classes. In this case, there are 7 intervals shown, indicating that there are 7 interval classes in the histogram.
11.
What is the frequency of the modal interval in the histogram above?
Correct Answer
6
12.
The histogram below shows data displayed in interval classes from 65-69.9, 70-74.9 etc.What is the frequency of the 95-99.9 interval class?
Correct Answer
1
Explanation
The frequency of the 95-99.9 interval class is 1. This means that there is only one data point within that interval.
13.
What is the frequency of the modal interval in the histogram above?
Correct Answer
6
14.
The histogram below displays data in class intervals from 165-169.9, 170-174.9 etc.What is the modal interval in the histogram above?
Correct Answer
170-174.9
Explanation
The modal interval in the histogram is the interval with the highest frequency, which in this case is 170-174.9. This means that there are more data points in this interval compared to any other interval in the histogram.
15.
The histogram below displays data in class intervals from 165-169.9, 170-174.9 etc.What is the frequency of the interval 195-199.9 in the histogram above?
Correct Answer
1
Explanation
The histogram provided displays data in class intervals, and the frequency of each interval represents the number of data points falling within that range. In this case, the frequency of the interval 195-199.9 is 1, indicating that there is only one data point falling within this range.
16.
What is the width of the interval class shown in the histogram above?
Correct Answer
8, 8 units
17.
The following data was collected by measuring the height of young pine trees in a garden nursery. The units used are centimetres (cm).65, 67, 67, 68, 70, 72, 72, 75, 76, 77, 77, 77, 78, 81, 83, 83, 84, 86, 87, 89, 89, 91, 96How wide would you make each interval if you wanted six or seven intervals?
Correct Answer
5cm, 5 centimetres, 5 cm
Explanation
The width of each interval determines the range of values that will fall within that interval. To determine the width, we need to find the range of the data and divide it by the desired number of intervals. In this case, the range of the data is 96-65 = 31. If we want six intervals, we divide 31 by 6 to get approximately 5.17. Since we cannot have a fraction of a centimeter, we round it down to the nearest whole number, which is 5. Therefore, the width of each interval would be 5cm.