問32
頻出度★★★
品質管理において, 測定値の存在する範囲を幾つかの区間に分け, 各区間に入るデータの度数を棒グラフで表したものはどれか。
平成28年度 春期 ITパスポート試験 問32
ストラテジ系企業活動 › 業務分析・データ利活用
This question's explanation and your answers so far.
解説
問 32
Incorrectア
A control chart is a line-type graph that plots measured values along the passage of time and draws a center line and upper and lower control limit lines to monitor whether a process is in a stable state. It does not represent a frequency distribution with bars for each interval, so it is incorrect.
Incorrectイ
A cause-and-effect diagram (fishbone diagram) is a diagram that organizes the factors influencing a certain result (characteristic) by branching them out like the bones of a fish. It is a diagram for cause analysis, not one that represents a frequency distribution as a bar chart, so it is incorrect.
Incorrectウ
A Pareto chart is a diagram in which items are arranged as bars in descending order of occurrence frequency or amount, with a cumulative-ratio line overlaid on top. It is used for priority management (identifying the vital few important items), not for dividing the range of measured values into intervals to represent a frequency distribution, so it is incorrect.
- エ
正解 A histogram (エ) is a column chart that divides the range of values a measurement can take into several intervals (classes) and uses the height of each bar to show the number of data (frequency) that fall into each interval. The wording in the question, “divide the range into intervals and show the frequency of each interval as a bar chart,” matches the definition of a histogram exactly. It is used to visually grasp the variability of data and the shape of the distribution (center, spread, skew), and it is one of the seven QC tools.
ここがポイント
- Histogram = a column chart that divides the range of measured values into intervals (classes) and shows the frequency of each interval by the height of a bar. Used to grasp the variability of data and the shape of the distribution.
- Distinguishing the seven QC tools: control chart = monitoring process stability, cause-and-effect diagram = organizing causes, Pareto chart = identifying priority items, histogram = grasping the distribution.
用語