The 68-95-99.7 rule tells us 68% of the probability is between -1 standard deviation and +1 standard deviation from the mean. So we expect 75% corresponds to slightly more than 1 standard deviation.
Usually the unit normal tables don't report the area between -σ and σ but instead a cumulative probability, the area between -∞ and σ. 75% corresponds to 37.5% in each half so a cumulative probability of 50%+37.5%=87.5%. We look that up in the normal table and get σ=1.15.
So we expect 75% of normally distributed data to fall within μ-1.15σ and μ+1.15σ
That's 288.6 - 1.15(21.2) to 288.6 + 1.15(21.2)
Answer: 264.22 to 312.98
Answer:
3
Step-by-step explanation:
9= 3*3
42=3*7*2
The formula for the lateral surface area of a right circular cone is:
where r is the radius of the base, and l is the slant height.
Plugging in the values we get:
Answer:
Each friend got 2 apples
Step-by-step explanation:
[original amount of apples]-[Apples Sally has after distribution] = [friends] x [number of apples]
Filling in the brackets, you get this equation.
15-9=3 x apples per friend
6=3 x apples per friend
2 = apples per friend
