Let u be the set of all words containing 7 letters(26 letters to the power 7)
Answer:
a) 0.0082
b) 0.9987
c) 0.9192
d) 0.5000
e) 1
Step-by-step explanation:
The question is concerned with the mean of a sample.
From the central limit theorem we have the formula:

a) 
The area to the left of z=2.40 is 0.9918
The area to the right of z=2.40 is 1-0.9918=0.0082

b) 
The area to the left of z=3.00 is 0.9987

c) The z-value of 1200 is 0
The area to the left of 0 is 0.5

The area to the left of z=1.40 is 0.9192
The probability that the sample mean is between 1200 and 1214 is

d) From c) the probability that the sample mean will be greater than 1200 is 1-0.5000=0.5000
e) 
The area to the left of z=-112.65 is 0.
The area to the right of z=-112.65 is 1-0=1
Answer:
30 mph
Step-by-step explanation:
time = distance/speed
If x represents Jane's speed along the summit then her total exploration time is ...
12/x + 40/(x -5) = 2 . . . . . hours
Multiplying by (x)(x -5), we get ...
12(x -5) +40(x) = 2(x)(x -5)
Dividing by 2 and subtracting the left side gives ...
x^2 -31x +30 = 0
(x -30)(x -1) = 0 . . . . . factor
Solutions are x = 30 and x = 1, values of x that make the factors zero. A speed of 1 mph makes no sense in this problem, so ...
Jane's speed along the summit was 30 mph.
Since the quotient of the two decimal numbers is 1, that tells use that they are the same number.
Since the sum of the two numbers equals 1 and both numbers are the same, then the answer must be 1 divided by 2. or .5
the fractions would be 1/2 and 1/2
5 pieces X 1.25 = 6.25
10-6.25 = 3.75 is the new length