Answer:
3 3/16
Step-by-step explanation:
Conversion a mixed number 8 1/2
to a improper fraction: 8 1/2=8×2+1/2=16+1/2=17/2
To find a new numerator:
a) Multiply the whole number 2 by the denominator 3. Whole number 2 equally 2×3/3= 6/
3
b) Add the answer from previous step 6 to the numerator 2. New numerator is 6 + 2 = 8
c) Write a previous answer (new numerator 8) over the denominator 3.
Two and two thirds is eight thirds
Divide: 17/2×8/3=17/2×3/8=17×3/2×8= 51/
16
Dividing two fractions is the same as multiplying the first fraction by the reciprocal value of the second fraction. The first sub-step is to find the reciprocal (reverse the numerator and denominator, reciprocal of 8/3 is 3/8) of the second fraction. Next, multiply the two numerators. Then, multiply the two denominators. In the following intermediate step, it cannot further simplify the fraction result by canceling.
In other words - seventeen halves divided by eight thirds = fifty-one sixteenths.
51/16
3 3/16
Answer:
The 80% confidence interval for the the population mean nitrate concentration is (0.144, 0.186).
Critical value t=1.318
Step-by-step explanation:
We have to calculate a 80% confidence interval for the mean.
The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.
The sample mean is M=0.165.
The sample size is N=25.
When σ is not known, s divided by the square root of N is used as an estimate of σM:
The degrees of freedom for this sample size are:
The t-value for a 80% confidence interval and 24 degrees of freedom is t=1.318.
The margin of error (MOE) can be calculated as:
Then, the lower and upper bounds of the confidence interval are:
The 80% confidence interval for the population mean nitrate concentration is (0.144, 0.186).
Answer: L = 29cm
Step-by-step explanation:
Let's go!!
To find any rectangle area, you have to apply this formula: A = L . w , where L is the length and w is the width.
So, we have w = L - 13 (the width is 13 less than the Length) and then, perimeter is 90 cm.
Well, I hope you remember that the perimeter of rectangle is 2L + 2W. In this case, 2L + 2w = 90
Then, you might to solve this system of equation:
2L + 2w = 90
w = L - 13
Simplifying the first equation, you'll have L + w = 45 (you can divide everything of 2).
Our new system:
L + w = 45
w = L - 13
Using the substituition method:
L + L - 13 = 45
2L = 58
L = 29 cm
the width is 29 - 13 = 16 cm
