Answer:
39
Step-by-step explanation:
x-3y=9
x-y=29
subtract
-2y=-20
y=10
x-10=29
x=39
5/8 that's how ratio of students that will buy lunch. so in order to find number students who will buy the lunch out of 720, just multiply 720 with 5/8 ie, 720x5/8 ie 450.
450 is answer
Answer:
And the deviation would be:
Step-by-step explanation:
For this case we have the following distribution given:
X 0 1 2 3 4 5 6
P(X) 0.3 0.25 0.2 0.12 0.07 0.04 0.02
For this case we need to find first the expected value given by:
And replacing we got:
Now we can find the second moment given by:
And replacing we got:
And the variance would be given by:
And the deviation would be:
Answer:
2 cm per hour
Step-by-step explanation:
1 hour lines up with 2cm
2 hours line up with 4cm
3 hours line up with 6cm
Answer: the answer is 120 or b
Step-by-step explanation: the answer is b