A = l × w. Substitute 72 into A and fill in the rest of the equation.
w = l - 1. Plug l - 1 into w
72 = l × (l - 1). Multiply l by (l - 1)
72 = l^2 - l. Subtract 72 from each side.
0 = l^2 - l - 72. Factor.
0 = (l + 8) (l - 9). Set each term equal to zero.
(l + 8) = 0. Subtract 8 from each side.
l = -8. Length cant be a negative number so let's try the other term.
(l - 9) = 0. Add 9 to each side.
l = 9. The length is 9.
Earlier we stated that the width is one less than the length, therefore, the width is 9 - 1 = 8.
The width is 8 units.
The first 4 on the left has a value of 400. The next 4 has a value of 40. The first 4 is in the hundreds place and the second 4 is in the 10's place.
Answer:
0.7698
Step-by-step explanation:
If you call your random variable 
, then what you are looking for is
because you want the probability of being <em>between 87 and 123.</em>
We need a table with of the normal distribution. But we can only find the table with 
and 
. Because of that, first we need to <em>normalize </em>our random variable:
(you can always normalize your variable following the same formula!)
now we can do something similar to our limits, to get a better expression:
And we transform our problem to a simpler one:
(see Figure 1)
From our table we can see that 
(this is represented in figure 2).
Remember that the whole area below the curve is exactly 1. So we can conclude that 
(because 0.8849 + 0.1151 = 1). We also know the normal distribution is symmetric, then
.
FINALLY:
Answer: $115.5
Step-by-step explanation:
The woman bought a coat for $99.95 and some gloves for $7.95. This means that the total amount of money that the woman would have paid for the coat without tax is
99. 95 + 7.95 = $107.9
If the sales tax was 7%, then the amount paid as sales tax would be
7/100 × 107.9 = 0.07 × 107.9 = $7.553
Therefore, the amount that she would pay to purchase the coat and the gloves is
107.9 + 7.553 = 115.453
= $115.5 rounded up to the nearest cent.
For this, let's have:
n represent each number, the number after it is its place in sequence
/ means divide
n1 /2 = n2, etc.
