Answer:
13.5
Step-by-step explanation:
It cost Jodi $44.88 to buy 12 gallons of gas. What was the cost per gallon of gas?
1 answer:
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Answer:
35.2% probability that the sample mean will be 246 pages or more
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal probability distribution
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean and standard deviation
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
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.
In this question, we have that:
What the probability that the sample mean will be 246 pages or more?
This is 1 subtracted by the pvalue of Z when X = 246. So
By the Central Limit Theorem
has a pvalue of 0.6480.
1 - 0.6480 = 0.3520
35.2% probability that the sample mean will be 246 pages or more
Answer:
Between 150 and 450
Step-by-step explanation:
We are going to find the number by resolving a system of linear equations.
First we write the system equations :
Where C : children, S : students and A : adults
The equation represents the ''full attendance''
The second equation :
This equation represents the totaled receipts.
The system :
has the following associated matrix :
By performing elementary matrix operations we find that the matrix is equivalent to
The new system :
Working with the equations :
Our solution vector is :
For example :
If 0 adults attended ⇒ A = 0
This verify the totaled receipts equation :
150($3)+600($5) = $ 3450
A ≥ 0 ⇒ If A = 0 ⇒ C = 150
C = 150 is the minimum children attendance
From the equation :
S ≥0
600 - 2A ≥ 0
600 ≥ 2A
300≥ A
A is restricted to the interval [ 0, 300]
When A = 0 ⇒ C = 150
When A = 300 ⇒C = 150 + A = 150 + 300 = 450
Children ∈ [ 150,450]
With C being an integer number (including 0)
Also S and A are integer numbers (including 0)