Q. \begin{tabular}{|l|l|}\hline Umur (Hari) & Frekuensi \\\hline 144−149 & 4 \\\hline 150−155 & 8 \\\hline 156−161 & 10 \\\hline 162−167 & 12 \\\hline 168−173 & 6 \\\hline\end{tabular}Data berikut adalah pengelompokan ternak berdasarkan umur (hari) disebuah desa. Kuartil ke−3 dari data tersebut adalah166.5167,5163.5162.5165.5
Find Q3 Position: To find Q3, we need to determine the position in the ordered data set. Q3 is the value below which 75% of the data lies.
Calculate Total Livestock: First, calculate the total number of livestock by summing the frequencies: 4+8+10+12+6.
Calculate Position of Q3: Total number of livestock = 4+8+10+12+6=40.
Find Value for Q3 Position: The position of Q3 is given by (43)×(total number of livestock+1). Let's calculate that.
Calculate Cumulative Frequencies: Position of Q3=(43)×(40+1)=(43)×41=30.75. So, we round up to the next whole number since we can't have a fraction of an observation.
Determine Interval for Q3: Position of Q3 = 31. Now, we need to find the value that corresponds to this position in the cumulative frequency distribution.
Use Linear Interpolation: Let's calculate the cumulative frequencies: 4, 4+8=12, 12+10=22, 22+12=34, 34+6=40.
Calculate Q3 Value: The 31st value falls in the interval 162−167, since the cumulative frequency just before this interval is 22 and it is 34 at the end of this interval.
Check for Mistakes: To find Q3 within the interval 162−167, we use linear interpolation. Q3=lower limit+[fn/4−F]×width of the interval, where F is the cumulative frequency before the interval, f is the frequency of the interval, and n is the total number of livestock.
Check for Mistakes: To find Q3 within the interval 162−167, we use linear interpolation. Q3=lower limit+[fn/4−F]∗width of the interval, where F is the cumulative frequency before the interval, f is the frequency of the interval, and n is the total number of livestock.$Q_3 = \(162\) + \left[\frac{\(31\) - \(22\)}{\(12\)}\right] * \(5\) = \(162\) + \left[\frac{\(9\)}{\(12\)}\right] * \(5\) = \(162\) + \(0\).\(75\) * \(5\) = \(162\) + \(3\).\(75\).
Check for Mistakes: To find \(Q3\) within the interval \(162-167\), we use linear interpolation. \(Q3 = \text{lower limit} + \left[\frac{(n/4 - F)}{f}\right] * \text{width of the interval}\), where \(F\) is the cumulative frequency before the interval, \(f\) is the frequency of the interval, and \(n\) is the total number of livestock.\(Q3 = 162 + \left[\frac{(31 - 22)}{12}\right] * 5 = 162 + \left[\frac{9}{12}\right] * 5 = 162 + 0.75 * 5 = 162 + 3.75\). \(Q3 = 162 + 3.75 = 165.75\). But this is not one of the options provided, so there must be a mistake.
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