Answer:
within ±1.96 standard deviations of the sample mean
Step-by-step explanation:
A 95% confidence interval is found using the formula C = 1 - α, and some other stuff, but let's focus on that for now. Using the formula:
.95 = 1 - α
α = .05
If α = .05, that means a 2-sided confidence interval would be found using the sample mean and the Z-score Z(subscript α/2), or Z.₀₂₅ because α AKA .05 divided by 2 = .025. From there, you take this either to your calculator or a Z-table (or perhaps you have a chart that lists the common CI values), and see that for the area to be .025 beneath a standard normal curve, your Z value is ±1.96 ("plus or minus" because we're considering a 2-sided confidence interval).
The turtle`s speed:
v t = 12 miles / hour = /*5,280
= 63,360 ft / hour = / : 3
= 21,120 yards / hour = / : 60
= 352 yards / minute
The boy`s speed:
v b = 4.4 ft/ s = / * 60/3
= 4.4 * 20 yards / minuet = 88 yards / minute
v t : v b = 352 : 88 = 4
The turtle swims 4 times faster than the boy.
Answer:
t = 2.5 s
Step-by-step explanation:
Suppose you have a water-balloon launcher. The balloon is 3 ft high when it leaves the launcher. Its equation is :
The above equation is a quadratic equation. The general equation is :
Here, a = 16, b = 38.8 and c = 3
The solution of quadratic equation is given by :
So, at t = 2.5 s the balloon is in air.
