Hello,
8/(x-7)=7/2
==>(x-7)*7=8*2
==>7x-49=16
==>7x=65
==> x =9+2/7
Answser A
Answer:
And rounded up we have that n=2663
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
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 population proportion have the following distribution
Solution to the problem
In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 99% of confidence, our significance level would be given by
and
. And the critical value would be given by:
The margin of error for the proportion interval is given by this formula:
(a)
And on this case we have that
and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
We can assume an estimated proportion of
since we don't have prior info provided. And replacing into equation (b) the values from part a we got:
And rounded up we have that n=2663
You can make a ratio of red to overall colors and then that will give you the fraction, you might have to simplify it
Start by converting 300 feet to miles and 2.92 seconds to hours.
300 feet 1 mile
----------- x -------------- = ?
1 5280 feet
2.92 sec 1 hr
----------------- * ---------------- = ?
1 3600 sec
Reduce each of the above fractions. Then convert 300 feet
-------------- to the
2.92 sec
equivalent speed / rate in mph using the converstion factors you derived earlier.
Answer:
Try your best and never give up take a deep breath and focus on it