Answer:
The 90% confidence interval for the mean combined fuel economy for Ford Explorers is between 22.95 and 23.63 mpg.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 16 - 1 = 15
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 15 degrees of freedom(y-axis) and a confidence level of
. So we have T = 1.7531
The margin of error is:

In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 23.29 - 0.34 = 22.95 mpg
The upper end of the interval is the sample mean added to M. So it is 23.29 + 0.34 = 23.63 mpg
The 90% confidence interval for the mean combined fuel economy for Ford Explorers is between 22.95 and 23.63 mpg.
Answer: 5/12 of the whole pizza
So we start we the whole pizza = 1
Then he ate 3/8:
1 - 3/8
And then 2/3 of what was left:
2/3(1 - 3/8)
2/3 - 1/4
8/12 - 3/12
5/12
Answer:
<em>It will take 9 years for the population to double</em>
Step-by-step explanation:
<u>Exponential Growth
</u>
The natural growth of some magnitudes can be modeled by the equation:

Where P is the actual amount of the magnitude, Po is its initial amount, r is the growth rate and t is the time.
The population of a city grows at a rate of r=8% = 0.08 per year. We are required to find when (t) the population will double, or P=2Po.
Substituting in the equation:

Simplifying:

Taking logarithms:

Applying the exponent property of logs:

Solving for t:

Calculating:

It will take 9 years for the population to double
Answer:
4
Step-by-step explanation:
It should be B I know how to do it