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.
Answer:
The measure of angle RST is 
Step-by-step explanation:
see the attached figure to better understand the problem
we know that
-----> equation A
-----> equation B
equate equation A and equation B




The measure of angle RST is equal to

Answer:
None
Step-by-step explanation:
There are actually 2 answers, 3 and -3. Although if you put it in a calculator, it would show "math error" or undefined. That's because the index is even (4) and the radicand is negative (-81)
48 girls are there. Given that there is a ratio of boys to girls of 7:8. Then divide 42 boys by 7 boys which equals 6. After, multiply 6 by 8 girls equals 48 girls.