On a planet far far away from Earth, IQ of the ruling species is normally distributed with a mean of 103 and a standard deviation of 15. Suppose one individual is randomly chosen. Let X = IQ of an individual. a. What is the distribution of X? X - N( b. Find the probability that a randomly selected person's IQ is over 92. Round your answer to 4 decimal places. c. A school offers special services for all children in the bottom 7% for IQ scores. What is the highest IQ score a child can have and still receive special services? Round your answer to 2 decimal places.
On a planet far far away from Earth, IQ of the ruling species is normally distributed with a mean of 103 and a standard deviation of 15. Suppose one individual is randomly chosen. Let X = IQ of an individual. a. What is the distribution of X? X - N( b. Find the probability that a randomly selected person's IQ is over 92. Round your answer to 4 decimal places. c. A school offers special services for all children in the bottom 7% for IQ scores. What is the highest IQ score a child can have and still receive special services? Round your answer to 2 decimal places.
MATLAB: An Introduction with Applications
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Author:Amos Gilat
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![### IQ Distribution and Statistics on a Distant Planet
#### Background
On a planet far away from Earth, the IQ of the ruling species is normally distributed with a mean of 103 and a standard deviation of 15. Suppose one individual is randomly chosen. Let \( X \) represent the IQ of an individual.
#### Questions and Answers
**a. What is the distribution of \( X \)?**
The distribution of \( X \) is given by:
\[ X \sim N(\text{mean}, \ \text{standard deviation}) \]
Input the respective mean and standard deviation into this normal distribution formula.
**b. Find the probability that a randomly selected person's IQ is over 92.**
To find this probability, use the standard normal distribution. You can find the Z-score using the following formula:
\[ Z = \frac{X - \mu}{\sigma} \]
where \( \mu \) is the mean (103) and \( \sigma \) is the standard deviation (15). After calculating the Z-score for 92, you can use a Z-table or statistical software to determine the probability. Round your answer to 4 decimal places.
**c. A school offers special services for all children in the bottom 7% for IQ scores. What is the highest IQ score a child can have and still receive special services?**
To find this IQ score, you will need to determine the Z-score corresponding to the bottom 7% of the normal distribution. Use the inverse of the normal distribution (i.e., the Z-table) to find this value, then convert it back to the original IQ scale:
\[ X = \mu + Z \sigma \]
Round your answer to 2 decimal places.
**d. Find the Inter Quartile Range (IQR) for IQ scores.**
The IQR represents the range between the 25th percentile (Q1) and the 75th percentile (Q3). You can find Q1 and Q3 by looking up the Z-scores for 0.25 and 0.75, respectively, and converting these back to the original IQ scale.
Calculate using the formulas:
\[ Q1 = \mu + Z_{0.25} \sigma \]
\[ Q3 = \mu + Z_{0.75} \sigma \]
\[ \text{IQR} = Q3 - Q1 \]
Round your answers to 2 decimal places.
This section](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F52bde6f1-de69-4d5b-bf13-f82b423cf0e9%2F64086c53-0833-4a82-af12-6abf1fa7b48a%2Fbnn5v0b_processed.png&w=3840&q=75)
Transcribed Image Text:### IQ Distribution and Statistics on a Distant Planet
#### Background
On a planet far away from Earth, the IQ of the ruling species is normally distributed with a mean of 103 and a standard deviation of 15. Suppose one individual is randomly chosen. Let \( X \) represent the IQ of an individual.
#### Questions and Answers
**a. What is the distribution of \( X \)?**
The distribution of \( X \) is given by:
\[ X \sim N(\text{mean}, \ \text{standard deviation}) \]
Input the respective mean and standard deviation into this normal distribution formula.
**b. Find the probability that a randomly selected person's IQ is over 92.**
To find this probability, use the standard normal distribution. You can find the Z-score using the following formula:
\[ Z = \frac{X - \mu}{\sigma} \]
where \( \mu \) is the mean (103) and \( \sigma \) is the standard deviation (15). After calculating the Z-score for 92, you can use a Z-table or statistical software to determine the probability. Round your answer to 4 decimal places.
**c. A school offers special services for all children in the bottom 7% for IQ scores. What is the highest IQ score a child can have and still receive special services?**
To find this IQ score, you will need to determine the Z-score corresponding to the bottom 7% of the normal distribution. Use the inverse of the normal distribution (i.e., the Z-table) to find this value, then convert it back to the original IQ scale:
\[ X = \mu + Z \sigma \]
Round your answer to 2 decimal places.
**d. Find the Inter Quartile Range (IQR) for IQ scores.**
The IQR represents the range between the 25th percentile (Q1) and the 75th percentile (Q3). You can find Q1 and Q3 by looking up the Z-scores for 0.25 and 0.75, respectively, and converting these back to the original IQ scale.
Calculate using the formulas:
\[ Q1 = \mu + Z_{0.25} \sigma \]
\[ Q3 = \mu + Z_{0.75} \sigma \]
\[ \text{IQR} = Q3 - Q1 \]
Round your answers to 2 decimal places.
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