Question

A population of individuals was exposed to lead contamination in drinking water at the concentration of 27 parts per billion (ppb). The following represents a small sample set from the population indicating the level of response to the contaminant rated on a scale from 1–20. Within your response, please explain how you calculated your answer (1 indicating minimal effects and 20 indicating maximum effects to the lead exposure). Given the data set 9, 12, 7, 15, 8, 9, 10, calculate the following results:a. mean,b. mode,c. median, andd. standard deviation.Your response should be at least 300 words in length.

Answer 1

Answer:

a) Mean - 10

b) mode - 9

c) Median - 9

d) SD - 2.708

Explanation:

A) Mean is the average of a given set of number in which the sum of all the number is divided by the number of entries

Thus, mean is equal to

$\frac{9+12+7+15+8+9+10}{7} \\= \frac{70}{7} \\= 10$

B) Mode is the most common number in a given series

Thus, mode is equal to 9 as it has appeared twice

C) Median

Number are arranged in ascending order

7, 8, 9, 9, 10, 12, 15

The middle number is the median i.e 9

D) Standard Deviation

Formula is square root of sum of $(X - mean )^2$ divided by $N-1$

$(9-10)^ 2+ (12-10)^2 + (7-10)^2 + (15-10)^2 + (8-10)^2+ (9-10)^2+ (10-10)^2\\= 1 + 4+ 9+ 25+ 4+ 1+ 0\\= 44$

$\sqrt{\frac{44}{7-1} } \\= 2.708$