Hi, i need help with this question. Thank you so much if you decide to help me :3
2 answers:
You might be interested in
There was a 66 
% increase from Sari's sales from November to December.
To find the percentage increase in her sales, we must first find the amount her sales increased. We can do that by subtracting the greeting cards sold in November from the number of greeting cards sold in December. Substituting values and simplifying, we get that she sold 200 more greeting cards in December.
To find what percent increase this is, we must find what percent 200 is of the number of greeting cards sold in November. We can do this by dividing 200 by the number of cards sold in November (300), and then multiplying by 100 (to make it a percent). Doing this, we get * 100 which gives us our answer of 66 %.
To find the percentage increase in her sales, we must first find the amount her sales increased. We can do that by subtracting the greeting cards sold in November from the number of greeting cards sold in December. Substituting values and simplifying, we get that she sold 200 more greeting cards in December.
To find what percent increase this is, we must find what percent 200 is of the number of greeting cards sold in November. We can do this by dividing 200 by the number of cards sold in November (300), and then multiplying by 100 (to make it a percent). Doing this, we get
Answer:
So then the minimum sample to ensure the condition given is n= 38
Step-by-step explanation:
Notation
represent the sample mean for the sample
population mean (variable of interest)
represent the population standard deviation
n represent the sample size
ME = 4 the margin of error desired
Solution to the problem
When we create a confidence interval for the mean the margin of error is given by this formula:
(a)
And on this case we have that ME =4 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 96% of confidence interval now can be founded using the normal distribution. The significance is . And in excel we can use this formula to find it:"=-NORM.INV(0.02;0;1)", and we got
, replacing into formula (b) we got:
So then the minimum sample to ensure the condition given is n= 38