Answer:
4
Step-by-step explanation:
The z-score is calculated by the following formula
z=(x-μ)/σ
where
μ=Population mean
σ=Population standard deviation
If the z-score for a specific sample mean is discussed then z-score is computed as
z=xbar-μ/σxbar.
where
μ=Population mean
σxbar=Sample standard deviation
As the population mean and mean of sampling distribution of mean are equal so, μ is used in above equation.
Now, the z-score is given
1.5=xbar-μ/σxbar
σxbar=xbar-μ/1.5.
Also we know that z-score corresponds to a score that is 6 points above mean which means that xbar-μ=6.
σxbar=6/1.5
σxbar=4.
Thus, the required sample standard deviation is 4.
Answer:
Let the current speed be "c";
Then the boat speed in still wate is "5c":
-----------------------
Upstream speed:
distance = 12 miles ; rate = 5c-c = 4c mph ; time = 12/4c = 3/c hrs
---------------------------
Downstream speed:
distance = 12 miles ; rate = 5c+c = 6c mph ; time = 12/6c = 2/c hrs
Step-by-step explanation:
Equation:
time + time = 2 1/2 hrs
3/c + 2/c = 5/2
Multiply thru by 2c to get:
6 + 4 = 5c
c = 2 mph (speed of the current)
5c = 10 mph (speed of the boat in still water)
Answer:
512
Step-by-step explanation:
8 fish per day x 64 days
512 fish
Multiply the diameter by PI which is 3.14 so that means the circumference would be 15.7.
The answer to your question is most likely A
