Statistics
Chapter 1- Compatibility Mode
Question and Answer
1. Prices (in pesos) of five ball pens are 22, 35, 15, 42, and 18. Let x be the price of
the ball pens in this sample. Find:
a. Σ𝑥
= 22+35+15+42+18
= 132 or ₱132.00
b. (Σx)2
= (132)²
= 17424 or ₱17,424.00
c. Σ𝑥 2
= (𝟐𝟐)²+(𝟑𝟓)²+(𝟏𝟓)² + (𝟒𝟐)²+(𝟏𝟖)²
= 484+1,225+225+1,764+324
= 4022 or ₱4,022.00
2. Eight randomly selected customers at 7-11 convenient store spent the following
amounts on groceries in a single visit: 115, 142, 45, 88, 125, 75, 18, and 37,
respectively. Let y denote the amount spent on groceries in a single visit. Find:
a. Σ𝑦
=115+142+45+88+125+75+18+37
= 645 or ₱645.00
b. (Σy)2
= (645)²
= 416,025 or ₱416,025.00
c. Σ𝑦 2
= (115)𝟐 +(142)𝟐 + (45)𝟐 + (88)𝟐 + (125)𝟐 + (75)𝟐 + (18)𝟐 + (37)𝟐
= 13,225+20,164+2,025+7,744+15,625+5,625+324+1,369
= 66,101 or ₱66,101.00
3. The following table lists five pairs of n and s values.
n 6 13 9 15 11
s 12 10 7 8 5
Chapter 1- Compatibility Mode
Question and Answer
1. Prices (in pesos) of five ball pens are 22, 35, 15, 42, and 18. Let x be the price of
the ball pens in this sample. Find:
a. Σ𝑥
= 22+35+15+42+18
= 132 or ₱132.00
b. (Σx)2
= (132)²
= 17424 or ₱17,424.00
c. Σ𝑥 2
= (𝟐𝟐)²+(𝟑𝟓)²+(𝟏𝟓)² + (𝟒𝟐)²+(𝟏𝟖)²
= 484+1,225+225+1,764+324
= 4022 or ₱4,022.00
2. Eight randomly selected customers at 7-11 convenient store spent the following
amounts on groceries in a single visit: 115, 142, 45, 88, 125, 75, 18, and 37,
respectively. Let y denote the amount spent on groceries in a single visit. Find:
a. Σ𝑦
=115+142+45+88+125+75+18+37
= 645 or ₱645.00
b. (Σy)2
= (645)²
= 416,025 or ₱416,025.00
c. Σ𝑦 2
= (115)𝟐 +(142)𝟐 + (45)𝟐 + (88)𝟐 + (125)𝟐 + (75)𝟐 + (18)𝟐 + (37)𝟐
= 13,225+20,164+2,025+7,744+15,625+5,625+324+1,369
= 66,101 or ₱66,101.00
3. The following table lists five pairs of n and s values.
n 6 13 9 15 11
s 12 10 7 8 5
