Answer:
The probability that <em>X</em> is less than 42 is 0.1271.
Step-by-step explanation:
The random variable <em>X </em>follows a Normal distribution.
The mean and standard deviation are:
E (X) = <em>μ</em> = 50.
SD (X) = <em>σ</em> = 7.
A normal distribution is continuous probability distribution.
The Normal probability distribution with mean µ and standard deviation σ is given by,

To compute the probability of a Normal random variable we first standardize the raw score.
The raw scores are standardized using the formula:

These standardized scores are known as <em>z</em>-scores and they follow normal distribution with mean 0 and standard deviation 1.
Compute the probability of (X < 42) as follows:

*Use a <em>z</em>-table for the probability.
Thus, the probability that <em>X</em> is less than 42 is 0.1271.
The normal curve is shown below.
Answer:
The range of z-score is given below as
Remove the vine, it is causing the population to decrease. No amount of animals etc. will be able to take care of the vine if the population is already decreasing.
1. Remove the vine.
Answer:


Step-by-step explanation:
Let x represent number of small candles and y represent number of large candles.
We have been given that Jonah needs to buy at least 20 candles. This means number of small and large candles should be greater than or equal to 20. We can represent this information in an inequality as:

We are also told that small candles cost $3.50, so cost of x small candles would be
.
Since large candles cost $5.00, so cost of y large candles would be
.
We are told that Jonah cannot spend more than $80, this means cost of x small candles and y large candles should be less than or equal to $80. We can represent this information in an inequality as:

Therefore, our required system of inequalities would be:

