Answer:
1191.4 ; 34.5
Step-by-step explanation:
Given the data:
29; 37; 38; 40; 58; 67; 68; 69; 76; 86; 87; 95; 96; 96; 99; 106; 112; 127; 145; 150
The sample variance and standard deviation can be obtained thus :
Σ(X - m)² / (n - 1)
Where, m = mean of the sample
n = sample size
The standard deviation equals, sqrt(variance )
Using a calculator:
The variance, σ² ;
Mean = Σx / n = 1681 / 20 = 84.05
(x -m)^2
[(29-84.05)^2 + (37-84.05)^2 + (38-84.05)^2 + (40-84.05)^2 + (58-84.05)^2 + (67-84.05)^2 + (68-84.05)^2 + (69-84.05)^2 + (76-84.05)^2 + (86-84.05)^2 + (87-84.05)^2 + (95-84.05)^2 + (96-84.05)^2 + (96-84.05)^2 + (99-84.05)^2 + (106-84.05)^2 + (112-84.05)^2 + (127-84.05)^2 + (145-84.05)^2 + (150-84.05)^2] / 19
22636.95 / 19
= 1191.4184 = 1191.42
Standard deviation = sqrt( Variance)
Standard deviation = sqrt(1191.4184)
Standard deviation = 34.516929 = 34.52
It would b 9 x (-3^(x-1))
Step-by-step explanation:
x+y=5
3x-2y+5=0
3x-2y= -5
x+y=5...... equation 1
3x-2y= -5....... equation 2
there fore make x the subject of the formula in equation 1
x=5-y.. equation 3
substitute equation three in equation 2
3(5-y)-2y=-5
15y-3y-2y=-5
10y=-5
divide both sides by 10
y=-5/10
y=-½
substitute y into equation 1
x+(-½)=5
x=5+½
x=5½
x=5½,y= -½
The answer for your problem is shown on the picture.
Answer:
C. as likely as not
Step-by-step explanation:
The teacher makes two groups with the same number and divides the student at random. The two groups have equal size, so the chance for someone to get picked into group 1 is 100%/2= 50%. The chance for someone to get picked into group 2 will be also 100%/2= 50%
The chance to get picked to be in group 1(50%) is the same as the chance to NOT get picked into group 1(50%). The word to explain this chance will be "as likely as not".