It would cost about $4.50
Answer:
a) The estimated standard deviation of the sampling distribution of the proportion is 0.023
b) the estimated standard deviation have been if he had surveyed only 100 customers is 0.046
Step-by-step explanation:
given information:
the number of sample, n = 400
sample proportion, p = 70% = 0.7
a) standard deviation of a sample proportion is
σ = 
= 
= 0.023
b) if n = 100, so
σ =
= 
= 0.046
The perimeter would be 30 feet.
Since the rectangle is 10 ft long and 5 ft wide, you have to all sides together
10 + 10 + 5 + 5 = 30
The probability is (1/6)^5 power. Since the locks are independent of each other, you can multiply the probabilities together. There are 6 possible numbers for each lock and there are 5 locks. So the probability is (1/6)^5 power.<span />
We can solve this problem using discriminant.
x^2-4x-12's discriminant is
(-4)^2-4*-12=16+48 which is clearly larger than 0
This means that it crosses over the axes 2 times.
In case you don't know what discriminant is, its in equation ax^2+bx+c
the discriminant is b^2-4ac.
If its positive it has 2 crosses with x axis, if negative then 0 crosses, if 0 then 1 cross.
Hope this helped at least a little bit :D
