12 +
Cambria M
3
3. Many people believe that the distribution of IQ scores follow a normal "bell curve." In reality is
this really how scores are distributed? The IQ scores of 60 fifth-grade students chosen at random
from one school are shown below.
134
110
118
109
96
139
134
124
122
122
81
133
97
125
113
115
105
145
109
106
101
125
113
116
89
110
100
117
110
130
123
102
102
103
118
136
109
129
101
131
117
112
124
127
114
82
142
117
90
114
112
124
139
101
137
127
108
102
114
a. Construct a histogram that effectively displays the distribution of IQ scores.
b. Describe what you see. Is the distribution normal?
c. Is this sample a good representation of fifth-graders IQ's? Explain.
of the frist 100

Quick translate "x is 12 units from 20" into an equation. what are the values of x being described? if you can answer any of my other questions that'd be great too

Which quadratic function best fits this data? x y 1 32 2 78 3 178 4 326 5 390 6 337 a. y=11.41x2+154.42x−143.9 b. y=−11.41x2+154.42x−143.9 c. y=11.41x2+154.42x+143.9 d. y=−11.41x2+154.42x+143.9

Aprisoner is trapped in a cell containing three doors. the first door leads to a tunnel that returns him to his cell after two days of travel. the second leads to a tunnel that returns him to his cell after three days of travel. the third door leads immediately to freedom. (a) assuming that the prisoner will always select doors 1, 2 and 3 with probabili- ties 0.5,0.3,0.2 (respectively), what is the expected number of days until he reaches freedom? (b) assuming that the prisoner is always equally likely to choose among those doors that he has not used, what is the expected number of days until he reaches freedom? (in this version, if the prisoner initially tries door 1, for example, then when he returns to the cell, he will now select only from doors 2 and 3.) (c) for parts (a) and (b), find the variance of the number of days until the prisoner reaches freedom. hint for part (b): define ni to be the number of additional days the prisoner spends after initially choosing door i and returning to his cell.