Answer:
Step-by-step explanation:
81
=
3
4
and
27
=
3
3
, so this equation can also be written as
3
4
x
=
3
3
(
x
+
2
)
=
3
3
x
+
6
.
Since the bases are now the same, we can equate exponents to get
4
x
=
3
x
+
6
so that
x
=
6
(technically this equating of exponents requires the fact that exponential functions (with base not equal to 1) are one-to-one functions).
(do u understand?)
<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>
THe number on the bottom is called the Notation
Answer: 0
Explanation:
-1/2n -(-1/2n)
= -1/2n + 1/2n
= 0
