Answer:
The probability that <em>X</em> is less than 42 is 0.1271.
Step-by-step explanation:
The random variable <em>X </em>follows a Normal distribution.
The mean and standard deviation are:
E (X) = <em>μ</em> = 50.
SD (X) = <em>σ</em> = 7.
A normal distribution is continuous probability distribution.
The Normal probability distribution with mean µ and standard deviation σ is given by,
To compute the probability of a Normal random variable we first standardize the raw score.
The raw scores are standardized using the formula:
These standardized scores are known as <em>z</em>-scores and they follow normal distribution with mean 0 and standard deviation 1.
Compute the probability of (X < 42) as follows:
*Use a <em>z</em>-table for the probability.
Thus, the probability that <em>X</em> is less than 42 is 0.1271.
The normal curve is shown below.
Answer:
P(x < 5) = 0.70
Step-by-step explanation:
Note: The area under a probability "curve" must be = to 1.
Finding the sub-area representing x < 5 immediately yields the desired probability.
Draw a dashed, vertical line through x = 5. The resulting area, on the left, is a trapezoid. The area of a trapezoid is equal to:
(average length)·(width, which here is:
2 + 5
----------- · 0.02 = (7/2)(0.2) = 0.70
2
Thus, P(x < 5) = 0.70
16 ÷ (4)(2) - 3(2) <span>÷ 2+1
16 </span>÷ 8 - 6 <span>÷ 3
2 - 2
0
Answer: 0</span>
Step 1: Find the slope:
This gives you 
, but we need to find b.
To find b, substitute in one (x,y) pair and it doesn't matter which one. I'll go with (4,-2):
![\begin{aligned}-2&=-\dfrac{3}{2}(4)+b\\[0.5em]-2&=-6+b\\[0.5em]4&=b\end{aligned}](https://tex.z-dn.net/?f=%5Cbegin%7Baligned%7D-2%26%3D-%5Cdfrac%7B3%7D%7B2%7D%284%29%2Bb%5C%5C%5B0.5em%5D-2%26%3D-6%2Bb%5C%5C%5B0.5em%5D4%26%3Db%5Cend%7Baligned%7D)
Now take that b-value and plug in into the slope-intercept form:
It's always a good idea to toss in the other x-value from the other point, to make sure it checks out.
<span>Using processing software (Excel) or even a decent scientific calculator. You input the values and generate the best fit cubic equation.
For number 1, the equation is
y = 8x10</span>⁻⁵ x³ - 0.0097 x² + 0.374 x + 1.083
where x is the number of years since 1900
y is the pounds cheese consumed
For number 2, the equation is
y = -3x10⁻⁵ x³ + 0.0028 x² + 0.2155 x + 1.7736
For number 3
P(-1) = 18
