4x=x-1+19 -> 4x=x+18 (then you minus 1x from both sides) -> 3x=18; x=6
Answer:
I'm pretty sure it's D.40 because it's the biggest number and 6+13+17 is only a bit bigger than 24. Also, all the numbers add up to 60 and 27 is only a bit less than 50% of 60
Answer:
The average number of phone calls in a 30 minute period is 3.
The probability to receive exactly 2 calls in that period is 0.224.
Step-by-step explanation:
If we are using the same Poisson distribution in the 2 hour period, then the average of phone orders in a reduced interval will be reduced according to that interval. Since 30 minutes is four times smaller than 2 hours, then the average number of phone orders per 30 minutes is 12 * 1/4 = 3. This can also be computed with a Rule of 3
120 minutes -------------> 12 orders
30 minutes ---------------> X orders
X = 30*12/120 = 3
Lets call Y the amount of phone orders received during a specific (random) 30 minute period. Since the average was 3, then Y has a Poisson distribution with parameter 3. The probability of Y being equal to 2 is

Thus, the probability to receive exactly 2 calls in a 30 minute period is 0.224.
0.05/1 min * 60 min = 0.05 * 60 = 3
<em>Therefore, the unit rate per hour is $3.</em>