Answer:
(29.46 mm, 29.54 mm).
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 43 - 1 = 42
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 42 degrees of freedom(y-axis) and a confidence level of 
. So we have T = 2.018
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 29.5 mm - 0.04mm = 29.46 mm
The upper end of the interval is the sample mean added to M. So it is 29.5 mm + 0.04mm = 29.54 mm
The 95% confidence level for the true mean width is: (29.46 mm, 29.54 mm).
Answer:
9 units²
Step-by-step explanation:
A differential of area is ...
dA = ((2y -y²) -(y² -4y))·dy = (-2y² +6y)·dy
The indefinite integral of this will be ...
a = -2/3y³ +6/2y²
Then the definite integral over the limits [0, 3] will be ...
(-2/3·3³ +3·3²) - 0 = 9 . . . . square units
If each ribbon will be 3.68 inches, and she needs 1000 ribbons, then multiply the two to find the total length of ribbon she needs.
3.68 x 1000 = 3680
So she will need 3680 inches of ribbon in total
Answer:
X= 110/7 or 15.7 or rounded to 16
Answer:
Step-by-step explanation:
An exponential function is of the form
where a is the initial value and b is the growth/decay rate. Our initial value is 64. That's easy to plug in. It goes in for a. So the first choice is out. Considering b now...
If the rate is decreasing at .5% per week, this means it still retains a rate of
100% - .5% = 99.5%
which is .995 in decimal form.
b is a rate of decay when it is greater than 0 but less than 1; b is a growth rate when it is greater than 1. .995 is less than 1 so it is a rate of decay. The exponential function is, in terms of t,
