Question

now determine the frequencies. the class frequency is the total number of data values in that class. recall that each data value should fall into exactly one class.
now examine the data set and determine how many data values fall into each class. note that with such a large number of values, you may find it helpful to order the data first.

28 33 33 34 35 37 38 39 39 41 43 43 44 44 44 44 45
45 45 45 47 47 47 47 47 47 48 49 50 50 50 51 51 51
51 51 52 52 52 52 52 55 55 56 57 58 59 61 73 81

complete the table.

class limits | class boundaries | frequency
28 - 38 | 27.5 - 38.5 | 7 ✓
39 - 49 | 38.5 - 49.5 | ❌
50 - 60 | 49.5 - 60.5 | 19 ✓
61 - 71 | 60.5 - 71.5 | 1 ✓
72 - 82 | 71.5 - 82.5 | 2 ✓

Explanation:

Step1: Identify data in 39 - 49

List data: 39,39,41,43,43,44,44,44,44,45,45,45,45,47,47,47,47,47,47,48,49.

Step2: Count the values

Count the numbers: 2 (39s) +1 (41) +2 (43s) +4 (44s) +4 (45s) +6 (47s) +1 (48) +1 (49) = 2+1+2+4+4+6+1+1 = 21? Wait, no, let's recount. Wait the data rows:

First row: 28,33,33,34,35,37,38,39,39,41,43,43,44,44,44,44,45 (17 numbers)

Second row: 45,45,45,47,47,47,47,47,47,48,49,50,50,50,51,51,51 (17 numbers)

Third row: 51,51,52,52,52,52,52,55,55,56,57,58,59,61,73,81 (16 numbers) Wait total data: 17+17+16=50.

Now, class 28-38: 28,33,33,34,35,37,38 → 7 (correct).

Class 39-49: numbers from 39 up to 49 (not including 50). Let's list all in 39-49:

39,39,41,43,43,44,44,44,44,45,45,45,45,47,47,47,47,47,47,48,49. Wait let's count:

39: 2

41:1 → 3

43:2 →5

44:4 →9

45:4 →13

47:6 →19

48:1 →20

49:1 →21? But total data is 50. Let's check other classes:

50-60: 19 (correct), 61-71:1 (61), 72-82:2 (73,81). 7+21+19+1+2=50. Yes, so 21. Wait but maybe I miscounted. Wait first row: after 38, the numbers are 39,39,41,43,43,44,44,44,44,45 (10 numbers in first row for 39-49? Wait first row: 28,33,33,34,35,37,38 (7), then 39,39,41,43,43,44,44,44,44,45 (10 numbers: 39,39,41,43,43,44,44,44,44,45 → 10). Second row: 45,45,45,47,47,47,47,47,47,48,49 (11 numbers: 45 (3), 47 (6), 48,49 → 3+6+2=11). So 10+11=21. Yes. So the frequency for 39-49 is 21.

Answer:

21