X = 47 + 9y
xy = 1860
y(47 + 9y) = 1860
47y + 9y² = 1860
9y² + 47y - 1860 = 0
> using a quadratic equation solver on a calculator but you can also use the quadratic equation = [-b+/- √(b²-4ac)]/(2a)
> only integer solution is x = 12
12y = 1860
y = 155
integers are 12 and 155
Answer:
x=30.6
Step-by-step explanation:
Answer:
A) Number of mango trees
B) Percentage of coconut trees = 60%
Total number of trees = 2230 trees
C)number of mango trees = 40% × 2230
D) 892 mango trees
Step-by-step explanation:
A) What is asked is the number of mango trees
B) We are given;
Percentage of coconut trees = 60%
Total number of trees = 2230 trees
C) Number sentence is defined as when we use an equation or inequality to describe an expression using numbers and signs.
We have percentage of coconut trees = 60%.
Thus, percentage of mango trees = 100% - 60% = 40%
In this case, the number sentence is; number of mango trees = 40% × 2230
D) number of mango trees = 40% × 2230 = 892
Answer:

Step-by-step explanation:
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The t distribution or Student’s t-distribution is a "probability distribution that is used to estimate population parameters when the sample size is small (n<30) or when the population variance is unknown".
The shape of the t distribution is determined by its degrees of freedom and when the degrees of freedom increase the t distirbution becomes a normal distribution approximately.
Data given
Confidence =0.99 or 99%
represent the significance level
n =16 represent the sample size
We don't know the population deviation 
Solution for the problem
For this case since we don't know the population deviation and our sample size is <30 we can't use the normal distribution. We neeed to use on this case the t distribution, first we need to calculate the degrees of freedom given by:

We know that
so then
and we can find on the t distribution with 15 degrees of freedom a value that accumulates 0.005 of the area on the left tail. We can use the following excel code to find it:
"=T.INV(0.005;15)" and we got
on this case since the distribution is symmetric we know that the other critical value is 
Set a porportion: 60/50=x/20 and solve for x=24