Inference for distributions

IQ scores for boys and girls (These data were collected by a researcher
at Purdue University. Treat these data as simple random samples from all
seventh-grade students in the district)

Problem: Here are IQ test scores of 31 seventh-grade girls in a Midwest
school district.

114 100 104 89 102 91
114 114 103 105

108 130 120 132 111 128
118 119 86 72

111 103 74 112 107 103
98 96 112 112


93

The IQ test scores of the 47 seventh-grade boys in the same district
are:

111 107 100 107 115 111 97
112 104 106 113

109 113 128 128 118 113 124
127 136 106 123

124 126 116 127 119 97 102
110 120 103 115

93 123 79 119 110 110 107
105 105 110 77

90 114 106

a). Find the mean IQ scores for girls and for boys. It is common for
boys to have somewhat higher scores on standardized tests. It that true?

b). Compute 95% T intervals of the Girls’ IQ’s and the Boys’
IQ’s and explain what these intervals mean.

c). Make a histogram for each set of data to determine whether each
distribution is reasonably symmetric with no outliers. If this is so, we
can use t- procedures—do your histograms indicate that we can use
t-procedures?

d). Give a 90% 2-Sample T interval confidence for the mean difference
between the mean IQ scores for all boys and girls in the district. Then
explain what this interval means.

Please help me make sense out of these questions. I am not understanding
well on what to do.

Thanks,

Sherry