For sample values Xx, Xx... the sample variance is s² = 1₁₁ Σ (x-x)², where x = 12 x, is the sample mean. i=1 (a) Show that the sample variance is unchanged if a constant c is added to or subtracted from each value in the sample. (b) Show that the sample variance becomes c² times its original value if each observation in the sample is multiplied by c.

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n
n
For sample values X1, X2,
n-
., X., the sample variance is s² = 11-1Σ (X; -x)², where x = -1 Σ x; is the sample mean.
n
i=1
i=1
(a) Show that the sample variance is unchanged if a constant c is added to or subtracted from each value in the sample.
(b) Show that the sample variance becomes c² times its original value if each observation in the sample is multiplied by c.
(a) If a constant c is added to or subtracted from each value in the sample, how do the sample values x, change?
Each x becomes (x; +c).
How does this change the sample mean X?
The sample mean
which
simplifies to x + nc.
simplifies to cx.
simplifies to x + c.
means the sample mean is x.
Transcribed Image Text:n n For sample values X1, X2, n- ., X., the sample variance is s² = 11-1Σ (X; -x)², where x = -1 Σ x; is the sample mean. n i=1 i=1 (a) Show that the sample variance is unchanged if a constant c is added to or subtracted from each value in the sample. (b) Show that the sample variance becomes c² times its original value if each observation in the sample is multiplied by c. (a) If a constant c is added to or subtracted from each value in the sample, how do the sample values x, change? Each x becomes (x; +c). How does this change the sample mean X? The sample mean which simplifies to x + nc. simplifies to cx. simplifies to x + c. means the sample mean is x.
n
n
For sample values x1, x2, ..., X, the sample variance is s² = -
n-1
n
Σ (x-x) ², where x = Σ x₁ is the sample mean.
i=1
i=1
(a) Show that the sample variance is unchanged if a constant c is added to or subtracted from each value in the sample.
(b) Show that the sample variance becomes c² times its original value if each observation in the sample is multiplied by c.
(a) If a constant c is added to or subtracted from each value in the sample, how do the sample values x; change?
Each x becomes (x; +c).
How does this change the sample mean x?
The sample mean
which
n
becomes (CX²).
i=1
remains unchanged,
n
becomes (x; +c).
i=1
Transcribed Image Text:n n For sample values x1, x2, ..., X, the sample variance is s² = - n-1 n Σ (x-x) ², where x = Σ x₁ is the sample mean. i=1 i=1 (a) Show that the sample variance is unchanged if a constant c is added to or subtracted from each value in the sample. (b) Show that the sample variance becomes c² times its original value if each observation in the sample is multiplied by c. (a) If a constant c is added to or subtracted from each value in the sample, how do the sample values x; change? Each x becomes (x; +c). How does this change the sample mean x? The sample mean which n becomes (CX²). i=1 remains unchanged, n becomes (x; +c). i=1
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