Let's start first by writing down the given:
σ = 100
sample mean = 450
sample size = 25
These information, plus the fact that we know that the population is approximately normally distributed, would tell us that we can use the
normal distribution curve in analyzing the problem.
A confidence interval of the mean is just a range statistically estimated to contain the population mean. For a 90% confidence interval, we would look at the Z-table and see where 90% of the data falls. We'll notice that it will fall within
1.645 standard deviations of the mean.
Next, we look for the standard error of the mean. This will have a formula

The standard error would just therefore be equal to

Lastly, we just get the product of the standard error and 1.645 and add it to 450 for the maximum value and subtract it to 450 for the minimum value.

ANSWER: 417.1<μ<482.9
Answer:
3m = 18
Step-by-step explanation:
9 + 12m = 6 + 15(m - 1)
9 + 12m = 6 + 15m - 15
3m = 18
Since x is the number of seconds it took the rock to hit the water, x is the value that we are looking for. When the rock hits the water, it's height is 0, therefore, f(x) = 0. So, we can set the expression on the right equal to 0, and solve for 0. Let's do just that:

We can divide by -16, nothing will happen because 0 divided by anything is 0:

To factor any trinomial in standard form (given below), we must find two numbers that add to "b" and multiply to "c":

So, for this specific question, let's find two numbers that add to -8 and multiply to 9. These are clearly 9 and -1. We can write it in this way now:

Both answers would be valid, but there can't be negative time, so your answer is
"It takes 9 seconds for the rock to reach the water."
For this case, the first thing we must do is define variables.
We have then:
t: number of hours
F (t): total charge
We write the function that models the problem:
Where,
b: represents an initial fee.
We must find the value of b.
For this, we use the following data:
Her total fee for a 4-hour job, for instance, is $ 32.
We have then:
From here, we clear the value of b:
Then, the function that models the problem is:
Answer:
the function's formula is:
