Answer:
the value of Z = 4
Step-by-step explanation:
i hope it helps :
ZZ + ZZ + Z + Z + Z = 100
And if we take value of z = 4 then
44 + 44 + 4 + 4 + 4 = 100
100 = 100
hence, Z = 4
The answer is B
4(4+10)
4*4=16
4*10=40 which will give you (16+40)
A) Variance = 10.24
B) Standard Deviation = 3.2
One of the measurements of dispersion is the standard deviation, which is exclusively used for quantitative data. It aids in determining if the data's mean is a suitable measurement to reflect the core value.
TIME FREQUENCY(f) MIDPOINT(x) d d² fd fd²
0 - 0.9 43 0.45 -3 9 -129 387
1.0 - 1.9 17 1.45 -2 4 -34 68
2.0 - 2.9 19 2.45 -1 1 -19 19
3.0 - 3.9 18 3.45 0 0 0 0
4.0 - 4.9 14 4.45 1 1 14 14
5.0 -5.9 16 5.45 2 4 32 64
∑f = 127
∑fd = -136
∑fd² = 552

Standard Deviation = 

√4.35 - √1.15
Standard Deviation = 3.2
(SD)² = (3.2)² = 10.24
Variance = 10.24
To know more about standard deviation, refer to this link :
brainly.com/question/12402189
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2100/1 or 4200/2, could be either