The data list shows the scores of ten students th Mr. Smith's math class. 61, 67, 81, 83, 87, 88, 89, 90, 98, 100
What is the standard deviation, to the nearest tenth, of the data If the scores represent a sample of Mr. Smith's students?
What is the standard deviation, to the nearest tenth, of the data if the scores represent the entire population of Mr.
Smith's students?
Sample:
Entire population:

Sample SD = 12.3

Population SD = 11.7.

Step-by-step explanation:

The mean of the scores

= The sum of the ten numbers  / 10

= 84.4

Now work out the differences of each score from this mean

61 - 84.4 = -23.4 ;  67 - 84.4 = -17.4

The other 8 differences are -3.4, -1.4, 2.6, 3.6, 4.6, 5.6, 13.6 and 15.6

Squares of these differences are :

547.56, 302.76, 11.56, 1.96, 6.76, 12.96, 21.16, 31.36, 184.96 and 243.36.

The Sum of these squares = 1364.4

The Sample Standard Deviation = √(sum of the squared difference/ (n-1)]

= √[1364.4/9]

= 12.3.

The Population Standard Deviation = √(sum of the squared difference/ (n)]

= √[1364.4/10]

= 11.7.

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)