A table shows the longest rivers in the world in miles.2341,2590,2718,2543,4160,2635,2734,3362,2744,2485,3395,2350,4000,3964,2600 thousands long.It has two questions.1. Choose an appropriate scale and interval size for a frequency table that will represent the data.Then make a freqency table. 2.Write a sentence or two to describe how the data are distributed among the intervals.Realy don't understand what they want me to do.
http://www.mathsteacher.com.au/year8/ch17_stat/03_freq/freq.htm
1. The scale goes from 2,000-4,500. Each interval has 500 miles in it.
Length (mi) Tally Frequency
2,000-2,500 III 3
2,500-3,000 IIIIIII 7
3,000-3,500 II 2
3,500-4,000 II 2
4,000-4,500 I 1
1. To create a frequency table for the given data, we need to choose an appropriate scale and interval size. Since the data ranges from 2341 to 4160 thousands, a suitable scale could be in increments of 500 thousands.
Frequency Table for Longest Rivers:
Interval | Frequency
----------------------------
2000-2499 | 2
2500-2999 | 6
3000-3499 | 4
3500-3999 | 1
4000-4499 | 2
2. The data are distributed among the intervals as follows:
- Two rivers have lengths between 2000 and 2499 thousands of miles.
- Six rivers have lengths between 2500 and 2999 thousands of miles.
- Four rivers have lengths between 3000 and 3499 thousands of miles.
- One river has a length between 3500 and 3999 thousands of miles.
- Two rivers have lengths between 4000 and 4499 thousands of miles.
This distribution indicates that most of the longest rivers in the world have lengths between 2500 and 2999 thousands of miles, with the number of rivers gradually decreasing as the lengths increase or decrease from this range.
For the first question, you are asked to create a frequency table for the given data. A frequency table is a way to organize data into intervals (ranges) and show how many data points fall within each interval.
To choose an appropriate scale and interval size, you need to consider the range of values in the data set. In this case, the data consists of the lengths of rivers, which range from 2341 to 4160 thousands of miles long.
Here's a step-by-step guide to creating a frequency table:
1. Determine the range of values: Subtract the smallest value (2341) from the largest value (4160) to get the range, which is 1819.
2. Decide on the number of intervals: Based on the range of values, you can choose the number of intervals. It's recommended to have around 5-10 intervals for a clear representation of the data. Let's choose 6 intervals.
3. Calculate the interval size: Divide the range by the number of intervals (1819 ÷ 6 = 303.17). Round this value up or down to a whole number for easier calculation. Let's round it down to 300.
4. Create the intervals: Begin with the smallest value (2341) and add the interval size successively to create the intervals. In this case, the intervals would be:
- 2000-2299
- 2300-2599
- 2600-2899
- 2900-3199
- 3200-3499
- 3500-3799
- 3800-4099
- 4100-4399
5. Count the frequencies: Go through the given data and count how many values fall within each interval. Create a tally or count for each interval.
6. Create the frequency table: Write down the intervals and their corresponding frequencies in a table format. The intervals are in a column on the left, and the frequencies are in a column on the right.
For the second question, you are asked to describe how the data are distributed among the intervals. To do this, you need to examine the frequencies in the frequency table.
Look for patterns or trends in the frequencies. For example, you might observe that some intervals have a higher frequency compared to others, suggesting a concentration of longer rivers in those ranges. Alternatively, if the frequencies are fairly equal across intervals, it indicates a more even distribution of river lengths.
To summarize, you need to choose an appropriate scale and interval size to create a frequency table for the given data, and then describe how the data are distributed among the intervals by analyzing the frequencies in the table.