For x = 4 within the distribution 2, 3, 4, 5, 6, the sum of squared deviations from x will be______________?
Show answer Hide answer
Answer: B. 10
Explanation
The arithmetic mean of the given numbers 2, 3, 4, 5, and 6 is exactly 4. Calculating squared deviations gives values of 4, 1, 0, 1, and 4 relative to the mean. Summing these individual squared differences together results in a total value equal to exactly 10. Squared deviations measure the dispersion of data points around a chosen central benchmark value. The formula for squared deviations involves subtracting the mean and squaring each resulting difference. This calculation forms the foundational mathematical basis for computing variance and standard deviation.
Data analysts compute squared deviations to understand how tightly clustered observations are around their average. Minimizing the sum of squared deviations is a core principle behind ordinary least squares regression. Quality control engineers use spread measures to detect abnormal variations in manufacturing output processes. Option A is incorrect because basic arithmetic mistakes lead to an inaccurate sum of squares. Option C underestimates the total dispersion by omitting several squared distance calculations entirely. Option D overestimates the dispersion due to incorrect arithmetic during the individual squaring steps.
- Subject
- Mathematics
- Category
- Statistics
- Topic
- —
- Difficulty
- medium
Related questions
Q1. Variance is minimized when deviations are measured relative to______________?
Show answer Hide answer
Answer: B. Mean
The sum of squared differences between data points and a constant is minimized at the mean. Calculus shows that taking the derivative of squared error with respect to the constant yields the mean. No other central locati...
Q2. If P(A/B)=1/4 alongside P(A∩B) =1/5, what is P(B) ________________?
Show answer Hide answer
Answer: A. 4/5
Conditional probability equals the intersection probability divided by the marginal probability of the conditioning event. Rearranging the conditional probability formula shows that the probability of B equals intersecti...
Q3. When variables x and y remain mutually independent, their correlation coefficient equals _____________?
Show answer Hide answer
Answer: D. 0
Independent variables show no linear relationship and yield a correlation coefficient of zero. Zero correlation means knowing the value of one variable provides no predictive power. The mathematical formulation of covari...
Q4. A distribution whose right tail extends further than its left tail is termed _________________?
Show answer Hide answer
Answer: B. Positively Skewed
Skewness direction is determined by the longer trailing tail of a frequency distribution. A right side extension indicates a long tail stretching toward higher numerical values. Statisticians formally designate this dist...
Q5. Under what condition does Var(T2)_______________?
Show answer Hide answer
Answer: A. Efficient
Efficiency in statistical inference refers strictly to having the smallest possible variance among estimators. An estimator is deemed efficient if no other unbiased estimator achieves a lower sampling variance. The Cramé...
Q6. For the transformation y= ax + b, the S.D. of y is _______________?
Show answer Hide answer
Answer: C. S.D. of x
For y = ax + b, the standard deviation of y is |a| * SD(x).