<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>
Assuming Lindsey takes 5 hours to mow a lawn, she earns from twelve lawns
12*70=$840.
If the above assumption is not correct, @funnyork2005 needs to clarify the question.
Answer: Choice A) $4500.33
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Explanation:
The formula you'll use is
F = P*(1+r)^t
where
F = final amount
P = initial amount
r = growth rate (in decimal form)
t = time in years
In this case,
F = unknown (this is what we're trying to figure out)
P = 3046
r = 0.05 (since 5% = 5/100 = 0.05)
t = 8
Plug those three known values into the formula and evaluate
F = P*(1+r)^t
F = 3046*(1+0.05)^8
F = 3046*(1.05)^8
F = 3046*1.4774554
F = 4500.3291484
F = 4500.33 ... round to the nearest penny
Answer:
-5
Step-by-step explanation:
an easy way to do it is to flip it so its 7-12 or you can do 12-7 and you get 5 then just add a - sign but thats my way and its weird lol
Answer:
$7.20
Step-by-step explanation:
