x = -9
-3x when x is 3 would be -3(3) = -9
The Disney trip was 5 years ago. Now, Erin is 16 and her sister is 8.
Rounded to one decimal place means to round to the nearest tenth (i.e. to the nearest 0.1)
4.25 (rounded to the nearest tenth) = <u><em>4.3</em></u>
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.
