Let X={11,19,18} be a set of observations of a random variable we know to have a bell-shaped distribution. What is σ
X
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? Please enter your response rnunded to 3 decimal places. Question 9 5 pts Let X={11,19,18} be a set of observations of a random variable we know to have a bell-shaped distribution. What is σ
X
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, i.e. the standard error of X
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? Please enter your response rounded to 3 decimal places.