Answer:
n=2/3
Step-by-step explanation:
Answer:
the answer is 0
Step-by-step explanation:
you distribute the 3 which gives
8 - 3k - 6 = 2 - 3k
then you combine like terms and end up with
2 - 3k = 2 - 3k
then you subtract 2 on each side which gives
- 3k = - 3k
and then when you have to keep combining like terms so you add the 3k on both sides which gives u 0
This pattern of question is always coming up. Since we can't easily guess, then let us set up simultaneous equation for the statements.
let the two numbers be x and y.
Multiply to 44. x*y = 44 ..........(a)
Add up to 12. x + y = 12 .........(b)
From (b)
y = 12 - x .......(c)
Substitute (c) into (a)
x*y = 44
x*(12 - x) = 44
12x - x² = 44
-x² + 12x = 44
-x² + 12x - 44 = 0.
Multiply both sides by -1
-1(-x² + 12x - 44) = -1*0
x² - 12x + 44 = 0.
This does not look factorizable, so let us just use quadratic formula
comparing to ax² + bx + c = 0, x² - 12x + 44 = 0, a = 1, b = -12, c = 44
x = (-b + √(b² - 4ac)) /2a or (-b - √(b² - 4ac)) /2a
x = (-(-12) + √((-12)² - 4*1*44) )/ (2*1)
x = (12 + √(144 - 176) )/ 2
x = (12 + √-32 )/ 2
√-32 = √(-1 *32) = √-1 * √32 = i * √(16 *2) = i*√16 *√2 = i*4*√2 = 4i√2
Where i is a complex number. Note the equation has two values. We shall include the second, that has negative sign before the square root.
x = (12 + √-32 )/ 2 or (12 - √-32 )/ 2
x = (12 + 4i√2 )/ 2 (12 - 4i√2 )/ 2
x = 12/2 + (4i√2)/2 12/2 - (4i√2)/2
x = 6 + 2i√2 or 6 - 2i√2
Recall equation (c):
y = 12 - x, When x = 6 + 2i√2, y = 12 - (6 + 2i√2) = 12 - 6 - 2i√2 = 6 - 2i√2
When x = 6 - 2i√2, y = 12 - (6 - 2i√2) = 12 - 6 + 2i√2 = 6 + 2i√2
x = 6 + 2i√2, y = 6 - 2i√2
x = 6 - 2i√2, y = 6 + 2i√2
Therefore the two numbers that multiply to 44 and add up to 12 are:
6 + 2i√2 and 6 - 2i√2
Answer:
(a) Approximately 68 % of women in this group have platelet counts within 1 standard deviation of the mean, or between 195.5 and 319.7.
(b) Approximately 99.7% of women in this group have platelet counts between 71.3 and 443.9.
Step-by-step explanation:
We are given that the blood platelet counts of a group of women have a bell-shaped distribution with a mean of 257.62 and a standard deviation of 62.1
Let X = <u><em>the blood platelet counts of a group of women</em></u>
So, X ~ Normal(
)
Now, the empirical rule states that;
- 68% of the data values lie within the 1 standard deviation of the mean.
- 95% of the data values lie within the 2 standard deviations of the mean.
- 99.7% of the data values lie within the 3 standard deviations of the mean.
(a) The approximate percentage of women with platelet counts within 1 standard deviation of the mean, or between 195.5 and 319.7 is 68% according to the empirical rule.
(b) The approximate percentage of women with platelet counts between 71.3 and 443.9 is given by;
z-score of 443.9 = 
= 
= 3
z-score of 71.3 =
= 
= -3
So, approximately 99.7% of women in this group have platelet counts between 71.3 and 443.9.
Yes -5/2 is lest than -2
(-5)/2 < -2
-2.5 < -2
true
