Answer:
1.99
Step-by-step explanation:
We have been given the heights of adult men in America are normally distributed, with a mean of 69.8 inches and a standard deviation of 2.61 inches. We are asked to find the z-score of height of man with 6 feet 3 inches.
We will use z-score formula to solve our given problem.
, where,
z = z-score,
x = Sample score,
= Mean,
= Standard deviation,
6 feet 3 inches = 72+3 inches = 75 inches
Therefore, the z-score for the man with height of 6 feet 3 inches is 1.99.
A little bit of trained eyeballing can help here. Let me tell you how I saw the answer without any computation.
Remember that the expansion of a squared binomial is
So, the square of a binomial has the following properties, which you can easily spot:
- It has three terms
- Two of them are perfect squares
- The third is twice the product of the two roots.
Well, in this case we do have three terms, and indeed is the square of 11x, and 1 is the square of itself. The only thing we have to check is that 22x is twice the product of 11x and 1, which is true.
So, the answer is
If you want to see some explicit calculations, just use the quadratic formula
to see that there is a double solution , and then use the formula
to come to the same conclusion.
You have the right answer 6p+2
The answer is B hope this helps