Let d = the length of the trail, miles
Note that
distance = speed * time
or
time = distance / speed.
The time, t₁, to travel the trail at 3 miles per hour is
t₁ = d/3 hours
The time, t₂, to travel back at 5 miles per hour is
t₂ = d/5 hours
Because the total time is 3 hours, therefore
t₁ + t₂ = 3
d/3 + d/5 = 3
d(1/3 + 1/5) = 3
d(8/15) = 3
Multiply each side by 15.
8d = 3*15 =45
d = 45/8 = 5 5/8 miles or 5.625 miles
Total distance = 2*d = 11.25 miles or 11 1/4 miles.
t₁ = 5.625/3 = 1.875 hours or 1 hour, 52.5 minutes
t₂ = 5.625/5 = 1.125 hours or 1 hour , 7.5 minutes
Answers ;
Time to travel at 3 miles per hour = 1.875 hours (1 hour, 52.5 minutes)
Time to return at 5 miles per hour = 1.125 hours (1 hour, 7.5 minutes)
Total distance traveled = 2*d = 11.25 miles.
Answer:
a) p-hat (sampling distribution of sample proportions)
b) Symmetric
c) σ=0.058
d) Standard error
e) If we increase the sample size from 40 to 90 students, the standard error becomes two thirds of the previous standard error (se=0.667).
Step-by-step explanation:
a) This distribution is called the <em>sampling distribution of sample proportions</em> <em>(p-hat)</em>.
b) The shape of this distribution is expected to somewhat normal, symmetrical and centered around 16%.
This happens because the expected sample proportion is 0.16. Some samples will have a proportion over 0.16 and others below, but the most of them will be around the population mean. In other words, the sample proportions is a non-biased estimator of the population proportion.
c) The variability of this distribution, represented by the standard error, is:
d) The formal name is Standard error.
e) If we divided the variability of the distribution with sample size n=90 to the variability of the distribution with sample size n=40, we have:

If we increase the sample size from 40 to 90 students, the standard error becomes two thirds of the previous standard error (se=0.667).
Is that the exact question? because the last part doesn't really make sense to me
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Answer: 13
Step-by-step explanation:
1. Harry has 20/20 sweets
2. Nadia takes 7/20 sweets
3. Your left with 13/20
There have to be at least 4 ducks recovered