Since the problem states "at least" we need to also find probability of 3 H or 4 H or 5 H
Now find the probability of flipping a head 4 times;
⁴
= (1/16)
Now probability of flipping a head 3 times: (4C3)(1/2)⁴ = 4/16
Probability of flipping a head 2 times; (4C2)(1/2)⁴=6/16
(1/16)+(4/16)+(6/16)=11/16
Probability of flipping a fair coin 4 times with at least 2 heads is 11/16.
Hope I helped :)
Answer: A golfer finds himself in two different situations on different holes. On the second hole he is 120 m from the green and wants to hit the ball 90 m
Step-by-step explanation:
Answer:
Kittens
Cute, soft
Sleeping, scratching, meowing
A cute soft ball
Kittens.
{ I made this up. Hope this helps :D }
<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>