Ok...we got 250 people
30% are French, 35% are Americans, 20% are Germans....thats 85%.
This means 15% are from other countries
3 not from other countries...
0.85 * 0.85 * 0.85 = 0.6
0.6(250) = 150 students <===
It should be C. richer scale
Answer:
Step-by-step explanation:
you have two supplementary angles,
both added up=180
7y+5y=12y
12y=180y=15
angle DBC=7y=15*7=105
<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:
72cm
Step-by-step explanation:
A=a^2
p=4a
p=4√A=4x√324=72 cm
