Which product is negative? a. –3 • 5 • (–6) • 4 b. –7 • (–3) • (–9) • 0 c. –4 • (–6) • (–3) • (–5) d. –3 • 4 • (–2) • (–7)

a) Mean = 8.6; Median = 6; Range = 4 to 15; Mid-range = 9.5; Standard deviation = 4.5

b) the sample minimum - 4; the first quartile  - 4; the median  - 6; the third quartile  - 14; the sample maximum - 15

Box plot attached

Step-by-step explanation:

As the question doesn't clearly mention the response of each of Andrew's friends, it is assumed as 15, 12, 5, 14, 4, 4, 6 as there should be 7 responses

a)

Step 1: Find the mean

Mean is the value obtained by dividing the sum of several quantities by their number

Mean = (sum of all values)/(number of values)

Mean = (15+12+5+14+4+4+6)/(7)

Mean = 60/7

Mean = 8.57

Mean = 8.6

Step 2: Find the median

Median denotes the value or quantity at the midpoint of a frequency distribution of values or quantities, meaning there is an equal probability of a value in the range being above or below it

Ordered distribution : 4, 4, 5, 6, 12, 14, 15

Median = 6

Step 3: Find the range

The range is the area of variation between upper and lower limits on a particular scale

Range = 4 to 15

Step 4: Find the mid-range

Mid-range is the arithmetic mean of the largest and the smallest values in a sample

Mid-range = (lowest value + highest value)/2

Mid-range = (4 + 15)/2

Mid-range = (19)/2

Mid-range = 9.5

Step 5: Find the standard deviation

Standard deviation is a value expressing by how much members of a group differ from the mean value for the group. It is calculated by taking the square root of the sum of the squares of the difference between each value and the mean divided by the number of values

Standard deviation = sqrt{sum[(mean - value)^2]/number of values}

Standard deviation = sqrt{[(8.57-4)^2 + (8.57-4)^2 + (8.57-5)^2 + (8.57-6)^2 + (8.57-12)^2 + (8.57-14)^2 + (8.57-15)^2]/7}

Standard deviation = sqrt{[(4.57)^2 + (4.57)^2 + (3.57)^2 + (2.57)^2 + (-3.43)^2 + (-5.43)^2 + (-6.43)^2)]/7}

Standard deviation = sqrt{[20.885 + 20.885 + 12.745 + 6.605 + 11.765 + 29.485 + 41.345]/7}

Standard deviation = sqrt{143.715/7}

Standard deviation = sqrt{20.531}

Standard deviation = 4.53

Standard deviation = 4.5

b)

The five number summary is a set of descriptive statistics that provides information about a set of values:

The box plot showing these values is attached