Hello!
The answer is 40. All we have to do is find the number of 16 year olds who spent between 25-35 minutes in social media. That is 145. The number of 13 year olds who spent the same amount of time is only 105, therefore 40 more 16 year olds spent between 25 and 35 minutes on social media.
Answer:
8/21
Step-by-step explanation:
2/7 ÷ 3/4
2/7 * 4/3
8/21
Answer:
48
Step-by-step explanation:
Answer:
a) 
b) 
c) 
d) 
And we can find this probability with this formula from the Bayes theorem:
Step-by-step explanation:
For this case we assume that the random variable X follows this distribution:

Part a
The probability density function is given by the following expression:


Part b
We want this probability:

And we can use the cumulative distribution function given by:

And replacing we got:

Part c
We want this probability:

And we can use the CDF again and we have:

Part d
We want this conditional probabilty:

And we can find this probability with this formula from the Bayes theorem:
