Bo w ler 1:104
Bow ler 2:117
Bo w ler 3:104
Bow ler 4:136Bo w ler 5:189
Bo w ler 6:109
Bo w ler 7:113
Bow ler 8:104Pr o b l em 1 Finding M easures of Central Tendency
Bowling What are the mean, median, and mode of the bowling scores below? Which
measure of central tendency best describes the scores?Think
Is t here an out lier in
t he d at a set?
Yes, the score 189 is
much higher than the
other scores.Mean:104 + 117 + 104 + 136 + 189 + 109 + 113 + 104 8 = 122The mean is the sum of
th e scores divided by
th e num ber o f scores.
Median: 104 104 104 109 113 1 1 7 1 3 6 1 8 9 List the d a ta in order.
109 + 113= 111 The m edian of an even num ber of data values is the
m ean o f th e tw o m iddle data values.Mode: (^104) The m ode is th e d a ta item th a t occurs th e m ost times.
Because there is an outlier, 189, the median is the best measure to describe the scores. The
mean, 122, is greater than most of the scores. The mode, 104, is the lowest score. Neither
the mean nor the mode describes the data well. The median best describes the data.
si G o t It? 1. Consider the scores from Problem 1 that do not include the outlier, 189.
What are the mean, median, and mode of the scores? Which measure of
central tendency best describes the data?
You can use an equation to find a value needed to achieve a given average.
Flan
What information is
unknown?
The grade on the fourth
exam is unknown. Use a
variable to represent this
grade.
Pr o b l em 2 Finding a Data Value
Grades Your grades on three exams are 80,93, and 91. What grade do you need on
the next exam to have an average of 90 on the four exams?
80 + 93 + 91 + x .: 9 0 U s e t h e f o r m u l a f o r t h e m e a n. L e t x = t h e g r a d e o n t h e f o u r t h e x a m.
2644+ x = 9 0 Simplify the numerator.
264 + x = 3 6 0 M u ltip ly each side by 4.
x = 9 6 S ubtract 2 6 4 from each side.
Your grade on the next exam must be 96 for you to have an average of 90.
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