Answer:
5
Step-by-step explanation:
take your price and subtract the monthly price
115-40=75
now you have the price of all your extra devices summed up
75÷15=5 extra devices
Answer:
a) The mean is 0.15 and the standard error is 0.056.
b) 1. Yes
Step-by-step explanation:
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean and standard deviation , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean and standard deviation .
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For proportions p, in samples of size n, the mean is and the standard error is . The Central Limit Theorem applies is np > 5 and np(1-p)>5.
In this question:
So
(a) Find the mean and the standard error of the distribution of sample proportions.
So the mean is 0.15 and the standard error is 0.056.
(b) Is the sample size large enough for the Central Limit Theorem to apply?
np = 40*0.15 = 6 > 5
np(1-p) = 40*0.15*0.85 = 5.1>5
So yes
If popcorn is p and water is w the equation can be written as
3p + w = 9.25
because there was 3 boxes of popcorn and one water (hence the coefficients) and the total is 9.25
then plug in 1.75 for w the price of water:
3p+ 1.75 = 9.25
you can move stuff around algebraically now (subtract 1.75 on both sides and divide by three on both aides) to get the cost of one box of popcorn (p).
The answer is 2.50