Yes his equations are correct
Total number of people = 125 + 100 = 225
Number of males = 100
Set as ratio
100:225
Simplify to 4:9 (can not simplify further without having decimals but you can’t have half a person)
The correct answer is 40 bars.
In order to find this amount we have to find when the y values are worth the same. Since both equations are equal to y, we can set them equal to each other to find a time when the y values are the same.
Company A = Company B
.75x = 10 + .50x ---> Now subtract .50x from both sides.
.25x = 10 ---> Now divide both sides by .25
x = 40
When x = 40 it will cost $30 from both companies.
Answer:
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".
Solution to the problem
The confidence interval for the mean is given by the following formula:
(1)
Since the Confidence is 0.95 or 95%, the value of
and
, and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.025,0,1)".And we see that
Now we have everything in order to replace into formula (1):
Answer: B
Step-by-step explanation:
The sampling distribution of the proportion of damaged trees is approximately Normal