Nick starts with 20 milligrams of a radioactive substance. The amount of the substance decreases by 14 each week for a number of
2 answers:
Answer:
Eric's expression is :
and Andrea's is :
In Eric's expression, 20 represents the initial amount of substance with which he has started the experiment. is the amount of substance left after each time period (in this case, each week).The variable w in this case represents the number of weeks.
Andrea's expression can be written as :
The one outside of parentheses represents the initial amount of the substance. The one inside of parentheses represents 100% of the original amount of the substance. 0.5 represents the 50% of the substance that is lost each time period. The variable w in this case represents the number of weeks.
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Answer:
a) The 99% confidence interval would be given by (5004.168;12603.832)
b) For this case we can use the lower bound for the confidence interval as estimation, on this case 5004.168. But we need to take in count that this value it's with 99% of confidence and 1% of significance and 1% of probability to commit type Error I
Step-by-step explanation:
1) 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)
s=5629 represent the sample standard deviation
n=20 represent the sample size
2) Part a
The confidence interval for the mean is given by the following formula:
(1)
In order to calculate the critical value we need to find first the degrees of freedom, given by:
Since the Confidence is 0.99 or 99%, the value of and
, and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.005,19)".And we see that
Now we have everything in order to replace into formula (1):
So on this case the 99% confidence interval would be given by (5004.168;12603.832)
3) Part b
For this case we can use the lower bound for the confidence interval as estimation, on this case 5004.168. But we need to take in count that this value it's with 99% of confidence and 1% of significance and 1% of probability to commit type Error I
The complete question in the attached figures
we know that
1 ft---------------> 0.083333 in
so
<span>24 inches high--------------> 24*0.083333=2 ft
</span><span>36 inches wide--------------> 36*0.083333=3 ft
</span><span>we will analyze each drawing
</span><span>
drawing a) scale 1/4 in/ 1 ft ----------> (1/4)/1=1/4
for a high of 2 ft-------------> 2*(1/4)=0.5 in
f</span>or a wide of 3 ft-------------> 3*(1/4)=0.75 in
drawing a) is not solution
drawing b) scale 1/2 in/ 1 ft ----------> (1/2)/1=1/2
for a high of 2 ft-------------> 2*(1/2)=1 in
for a wide of 3 ft-------------> 3*(1/2)=1.5 in
drawing b) is not solution
drawing c) scale 1/2 in/ 1 ft ----------> (1/2)/1=1/2
for a high of 2 ft-------------> 2*(1/2)=1 in
for a wide of 3 ft-------------> 3*(1/2)=1.5 in
drawing c) is not solution
drawing d) scale 1 in/ 1 ft ----------> (1)/1=1
for a high of 2 ft-------------> 2*(1)=2 in
for a wide of 3 ft-------------> 3*(1)=3 in
drawing d) is a solution
the answer is
The correct model of the flag is the drawing D
we know that
1 ft---------------> 0.083333 in
so
<span>24 inches high--------------> 24*0.083333=2 ft
</span><span>36 inches wide--------------> 36*0.083333=3 ft
</span><span>we will analyze each drawing
</span><span>
drawing a) scale 1/4 in/ 1 ft ----------> (1/4)/1=1/4
for a high of 2 ft-------------> 2*(1/4)=0.5 in
f</span>or a wide of 3 ft-------------> 3*(1/4)=0.75 in
drawing a) is not solution
drawing b) scale 1/2 in/ 1 ft ----------> (1/2)/1=1/2
for a high of 2 ft-------------> 2*(1/2)=1 in
for a wide of 3 ft-------------> 3*(1/2)=1.5 in
drawing b) is not solution
drawing c) scale 1/2 in/ 1 ft ----------> (1/2)/1=1/2
for a high of 2 ft-------------> 2*(1/2)=1 in
for a wide of 3 ft-------------> 3*(1/2)=1.5 in
drawing c) is not solution
drawing d) scale 1 in/ 1 ft ----------> (1)/1=1
for a high of 2 ft-------------> 2*(1)=2 in
for a wide of 3 ft-------------> 3*(1)=3 in
drawing d) is a solution
the answer is
The correct model of the flag is the drawing D