Question

the iq scores of 50 students are given below.
(a) construct a grouped - frequency distribution for the data. use 85 - 89 for the first class and use the same width for each subsequent class.
class frequency
85 - 89

Explanation:

Step1: Determine class width

The first class is 85 - 89, so the class width is \(89 - 85= 4\).

Step2: Define classes

The classes will be 85 - 89, 90 - 94, 95 - 99, 100 - 104, 105 - 109, 110 - 114, 115 - 119, 120 - 124.

Step3: Count frequencies

For the class 85 - 89: Count the number of scores in this range from the data set. Let's assume the data is: [100, 87, 91, 96, 114, 118, 96, 107, 115, 85, 113, 109, 111, 112, 106, 114, 98, 94, 104, 95, 114, 87, 101, 118, 91, 90, 93, 93, 111, 96, 87, 115, 106, 95, 100, 103, 114, 106, 101, 101, 90, 104, 96, 85, 105, 105, 111, 99, 110, 93].

• Class 85 - 89: Count the values 85, 87, 87, 87, 85. Frequency = 5.
• Class 90 - 94: Values 91, 94, 98, 94, 91, 90, 93, 93, 96, 90, 93, 96. Frequency = 12.
• Class 95 - 99: Values 96, 95, 95, 96, 99. Frequency = 5.
• Class 100 - 104: Values 100, 107, 104, 106, 104, 100, 103, 104, 101, 101, 101. Frequency = 11.
• Class 105 - 109: Values 106, 105, 106, 105. Frequency = 4.
• Class 110 - 114: Values 114, 113, 111, 112, 114, 114, 111, 114, 111. Frequency = 9.
• Class 115 - 119: Values 115, 118, 115, 118. Frequency = 4.
• Class 120 - 124: Frequency = 0.

Class	Frequency
90 - 94	12
95 - 99	5
100 - 104	11
105 - 109	4
110 - 114	9
115 - 119	4
120 - 124	0

Answer:

Class	Frequency
90 - 94	12
95 - 99	5
100 - 104	11
105 - 109	4
110 - 114	9
115 - 119	4
120 - 124	0