Answer:
Mean = 35
Variance = 291.7
Step-by-step explanation:
Data provided in the question:
X : 1, 2, 3, 4, 5, 6
All the data are independent
Thus,
The mean for this case will be given as:
Mean, E[X] = 
or
E[X] = 
or
E[X] = 3.5
For 10 days, Mean = 3.5 × 10 = 35
And,
variance = E[X²] - ( E[X] )²
Now, for this case of independent value,
E[X²] = 
or
E[X²] = 
or
E[X²] = 
or
E[X²] = 15.167
Therefore,
variance = E[X²] - ( E[X] )²
or
variance = 15.167 - 3.5²
or
Variance = 2.917
For 10 days = Variance × Days²
= 2.917 × 10²
= 291.7
Answer:
Speed of boat in still water is 26km/hr
Step-by-step explanation:
Let the speed of boat in still water be x and speed of stream by y.
Speed at which it went upstream would be (x-y) and the speed at which it went downstream would be (x+y). According to question x+y=24 and x-y=28. x=26 and y=-2.
Answer:
about 6230 N
Step-by-step explanation:
The mass is given to 3 significant figures, so we need a value for the acceleration due to gravity that is at least 3 significant figures. The standard value is 9.80665 m/s². Using that, the force is ...
... F = ma = (635 kg)(9.80665 m/s²) = 6227.22275 N
Since the mass is only good to 3 significant figures, the force must be rounded to that precision: 6230 N.
