Regina leased a car for $380 per month. Her new lease is $475 per month. What is the percent increase in the monthly cost of her
2 answers:
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Answer:
17. See below
18. 750
Step-by-step explanation:
17. Since the lollipops are being sold at the same price, 50 cents, for each one sold, they make a constant amount of money. For each increase in lollipops sold, there is a constant increase in money made, and thus the situation is a linear function.
18. To solve this equation, let's say y is the money made at the convention in dollars and x is the number of lollipops sold. If the principal gave them 125 dollars before they sold any lollipops (0 lollipops sold), then 125 is the y-intercept of the function, and in the equation y=mx+b, b=125. If each lollipop costs 50 cents (half of a dollar), then for each lollipop, x, sold, .5 dollars are made and are added to the profit, y. Thus, .5 dollars is the slope. The equation then becomes:
Now, if they need 500 dollars, y is thus equal to 500 dollars. Solving the equation:
Thus, 750 lollipops must be sold.
Answer:
So the answer for this case would be n=11 rounded up to the nearest integer
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".
represent the sample mean for the sample
population mean (variable of interest)
represent the population standard deviation
n represent the sample size
Solution to the problem
The confidence interval for the mean is given by the following formula:
(1)
The confidence interval for this case is given by: (740, 920)
We can find the estimate for the mean and we got:
and the margin of error is given by :
The margin of error is given by this formula:
(a)
And on this case we have that ME =90 and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
The critical value for 95% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.025;0;1)", and we got , replacing into formula (b) we got:
So the answer for this case would be n=11 rounded up to the nearest integer