B, C, and D are all correct.
Answer: About 99.7% IQ scores falls within 43 and 157.
Step-by-step explanation:
According to the empirical rule , if a data follows normal distribution then about 99.7% of the population lies with in three standard deviations from mean.
Given: IQ test have a bell-shaped distribution with a mean of 100 and a standard deviation of 19.
Since , the graph of normal distribution is bell-shaped , it mean that IQ scores follow normal distribution.
Then, About 99.7% IQ scores falls within Mean ± 3 (Standard deviation).
i.e. About 99.7% IQ scores falls within 100± 3(19).
i.e. About 99.7% IQ scores falls within 100- 57 and 100+57.
i.e. About 99.7% IQ scores falls within 43 and 157.
Therefore , by empirical rule
About 99.7% IQ scores falls within 43 and 157.
<h2>Answer: A trapezoid with bases of 6 mm and 14 mm and a height of 8 mm </h2>
The parallelogram in the figure has an area of 
, according to the following formula, which works for all rectangles and parallelograms:
(1)
Where 
is the base and 
is the height
The<u> area of a triangle</u> is given by the following formula:
(2)
So, for option A:
Now, the <u>area of a trapezoid </u>is:
(3)
For option B:
For option C:
>>>>This is the correct option!
For option D:
<h2>Therefore the correct option is C</h2>
C. 4x + y = 21
4(3) + 9 = 21
12 + 9 = 21
21 = 21
At 08:00 there are 18 bags
At 08:10 there are an extra 10 produced = 28 but 1/2 are consumed leaving 14
At 08:20 there are an extra 10 produced = 24 but 1/2 are consumed leaving 12
At 08:30 there are an extra 10 produced = 22 but 1/2 are consumed leaving 11
At 08:36 another 6 have been produced = 17 bags
