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Part 1

The following frequency histogram represents the IQ scores of a random sample of seventh-grade students. IQs are measured to the nearest whole number. The frequency of each class is labeled above each rectangle. Use the histogram to answers parts (a) through (g).

IQs of 7th Grade Students 60708090100110120130140150160020406080IQscoresFrequency221441584131821 A histogram titled "IQs of Seventh Grade Students" with a horizontal axis labeled "IQ Scores" from less than 60 to 160 plus in increments of 10 and a vertical axis labeled "Frequency" from 0 to 80 in increments of 10 contains vertical bars of class width 10 with heights as follows, where the horizontal axis ranges are listed first and the heights are listed second: 60 to 70, 2; 70 to 80, 2; 80 to 90, 14; 90 to 100, 41; 100 to 110, 58; 110 to 120, 41; 120 to 130, 31; 130 to 140, 8; 140 to 150, 2; 150 to 160, 1. Each bar is labeled with its height.

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Part 1

(a)How many students were sampled?

200200

students

Part 2

(b)Determine the class width.

The class width is

1010.

Part 3

(c)Identify the classes and their frequencies. Choose the correct answer below.

A.

60-69,

22;

70-79,

22;

80-89,

1414;

90-99,

4141;

100-109,

5858;

110-119,

4141;

120-129,

31 ;31;

130-139,

88;

140-149,

22;

150-159, 11

Your answer is correct.

B.

65,

22;

75,

22;

85,

1414;

95,

4141;

105,

5858;

115,

4141;

125,

3131;

135,

88;

145,

22;

155, 11

C.

60-70,

22;

70-80,

22;

80-90,

1414;

90-100,

4141;

100-110,

5858;

110-120,

4141;

120-130,

31 ;31;

130-140,

88;

140-150,

22;

150-160, 11

Part 4

(d)Which class has the highest frequency?

A.105

105105

B.100 dash 109

100 dash 109100-109

Your answer is correct.

C.100 dash 110

100 dash 110100-110

D.90 dash 99

90 dash 9990-99

Part 5

(e)Which class has the lowest frequency?

A.150 dash 160

150 dash 160150-160

B.60 dash 69

60 dash 6960-69

C.150 dash 159

150 dash 159150-159

Your answer is correct.

D.155

155155

Part 6

(f)What percent of students had an IQ of at least

120120?

enter your response here%

(Type an integer or a decimal. Do not round.)