Answer:
If a, b and c are in arithmetic progression, that means that a + c = 2b. So a + b, a + c and b + c are also in arithmetic progression.
This might help.
Answer:
Step-by-step explanation:
(x−a)(x−b)=x2−(a+b)x+ab
Now, this with the third bracket.
(x2−(a+b)x+ab)(x−c)=x3−(a+b+c)x2+(ac+bc+ab)x−abc
But there’s another way to do this, which is easier. Assume the given expression is equal to 0, then, we can form a cubic equation as
x3−(sum−of−roots)x2+(product−of−roots−taken−two−at−a−time)x−(product−of−roots) , which is essentially what we got above.
<span>n = 5
The formula for the confidence interval (CI) is
CI = m ± z*d/sqrt(n)
where
CI = confidence interval
m = mean
z = z value in standard normal table for desired confidence
n = number of samples
Since we want a 95% confidence interval, we need to divide that in half to get
95/2 = 47.5
Looking up 0.475 in a standard normal table gives us a z value of 1.96
Since we want the margin of error to be ± 0.0001, we want the expression ± z*d/sqrt(n) to also be ± 0.0001. And to simplify things, we can omit the ± and use the formula
0.0001 = z*d/sqrt(n)
Substitute the value z that we looked up, and get
0.0001 = 1.96*d/sqrt(n)
Substitute the standard deviation that we were given and
0.0001 = 1.96*0.001/sqrt(n)
0.0001 = 0.00196/sqrt(n)
Solve for n
0.0001*sqrt(n) = 0.00196
sqrt(n) = 19.6
n = 4.427188724
Since you can't have a fractional value for n, then n should be at least 5 for a 95% confidence interval that the measured mean is within 0.0001 grams of the correct mass.</span>
Answer:x=143
Step-by-step explanation: set 128=X-15 add 15 to both sides
<span>To find the answer we need to find the raduis
Circumference = 2πr
r=</span>
r=
= 104.08
The diameter is 2r, hence the diameter is 208.16
If the rate to cross is 6ft. per second, time can be found by dividing the raduis by 6
It would take 34.7 seconds
