At 95% confidence interval, the z score is 1.96. Using the
formula:
Confidence Interval = x ± z s / sqrt (n)
where x is the average time served, s is standard deviation
and n is number of samples
Confidence interval = 7.5 ± (1.96 * 3) / sqrt (400)
Confidence interval = 7.5 ± 0.294
<span>Confidence interval = 7.206 to 7.794</span>

so hmm notice, we use the decimal format for the percent, namely 15% is just 15/100 and 5% is just 5/100 and so on
whatever the amounts of "x" and "y" are, they must add up to 100 grams
thus x + y = 100
and whatever the concentrated amounts are, they'll add up to (100)(0.15)
thus

solve for "x", to see how much 5% alloy will be needed
what about "y"? well y = 100 -x
LABC is a 30°angle point B is at (3,2)
Answer:
Step-by-step explanation:
Since r=2 and |r|>1 the sum does not converge to any value. The sum does not exist for this infinite geometric series.