Answer:
Step-by-step explanation:
Hello!
The variable of interest is:
X: height of seaweed.
X~N(μ;σ²)
μ= 10 cm
σ= 2 cm
You have to find the value of the variable X that separates the bottom 0.30 of the distribution from the top 0.70
P(X≤x)= 0.30
P(X≥x)= 0.70
Using the standard normal distribution you have to find the value of Z that separates the bottom 0.30 from the top 0.70 and then using the formula Z= (X-μ)/σ translate the Z value to the corresponding X value.
P(Z≤z)= 0.30
In the body of the table look for the probability of 0.30 and reach the margins to form the Z value. The mean of the distribution is "0" so below 50% of the distribution you'll find negative values.
z= -0.52
Now you have to clear the value of X:
Z= (X-μ)/σ
Z*σ= X-μ
X= (Z*σ)+μ
X= (-0.52*2)+10= 8.96
The value of seaweed height that divides the bottom 30% from the top 70% is 8.96 cm
I hope this helps!
545,999 rounded to the nearest hundred thousand is 546,000.
We know that
The volume of a circular truncated cone=(1/3)*pi*[r1²+r1*r2+r2²]*h
where
r1=7/2-----> 3.5 in
r2=10/2----> 5 in
h=12 in
volume of a circular truncated cone=(1/3)*pi*[3.5²+3.5*5+5²]*12
volume=688 in³
the answer is
688 in³
Answer:
He should drive his car at a speed of 81.25 kilometers per hour.
Step-by-step explanation:
With a velocity of 65 kilometers per hour, he reaches home in 50 minutes. What speed he needs to reach home 10 minutes earlier, that is, in 50 - 10 = 40 minutes?
To solve this, we use the relation between inverse proportion variables(as the velocity increases, time needed decreases), that is, a rule of three with line multiplication, instead of cross. So
65 kilometers per hour - 50 minutes
x kilometers per hour - 40 minutes
So
He should drive his car at a speed of 81.25 kilometers per hour.
Let wind speed = x mph
when she rode 2 miles against the wind we have:-
speed = distance / time so
20 - x = 2 / t -------(1) where t is the time she took.
when riding with the wind we have
20 + x = 3 / t--------(2) adding equations (1) and (2):-
40 = 2/t + 3/t
40 = 5/t
t = 5/40 = 1/8 hr
x = 20 - 2 / 1/8 = 20 - 16 = 4
Wind speed was 4 mph Answer
