Answer:
The other factor is 
Step-by-step explanation:
we know that


In this problem we have

and
-----> because is a factor
substitute and solve for b

so

Verify in the second equation
----->
----->
--> is ok
The other factor is 
Answer: 0.951%
Explanation:Note that in the problem, the scenario is either the adult is using or not using smartphones. So, we have a yes or no scenario involved with the random variable, which is the number of adults using smartphones. Thus, the number of adults using smartphones follows the binomial distribution.
Let x be the number of adults using smartphones and n be the number of randomly selected adults. In Binomial distribution, the probability that there are k adults using smartphones is given by

Where p = probability that an adult is using smartphones = 54% (since 54% of adults are using smartphones).
Since n = 12 and k = 3, the probability that fewer than 3 are using smartphones is given by

Therefore, the probability that there are fewer than 3 adults are using smartphone is 0.00951 or
0.951%.
Well the answer couldn’t be C because the arrow has to go to the right not left because for the > in the equation
So the answer has to be D because the dot it on -.5 and the arrow is going right