People spend an average of 7 hours per day on their home computers with a standard deviation of 1hour. What proportion spends at least 5 hours per day on their home computers? (enter the answeras a percent rounded to the nearest hundredth as needed)

People spend an average of 7 hours per day on their home computers with a standard deviation of 1hour What proportion spends at least 5 hours per day on their h class=

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Solution;

From the given question, we have

[tex]\begin{gathered} \mu=7 \\ \sigma=1 \end{gathered}[/tex]

To evaluate the proportion of people that spend at least 5 hours per day on their home computers,

Step 1: Evaluate the z score value.

The z score value is expressed as

[tex]\begin{gathered} z=\frac{x-\mu}{\sigma} \\ where \\ x\implies sample\text{ value} \\ \mu\implies mean\text{ value} \\ \sigma\implies standard\text{ deviation} \end{gathered}[/tex]

In this case,

[tex]x=5[/tex]

thus, we have the z score value to be evaluated as

[tex]z=\frac{5-7}{1}=-2[/tex]

Step 2: Evaluate the probability that people will spend at least 5 hours per day on their home computers,

From the normal distribution table, we have

This implies that

[tex]P(x\ge5)=P(z\ge-2)=0.977249868052[/tex]

Hence, the proportion that spends at least 5 hours per day on their home computers is evaluated to be

[tex]\begin{gathered} 0.977249868052\times100 \\ =97.7249868052 \\ \approx97.72\%\text{ \lparen nearest hundredth\rparen} \end{gathered}[/tex]

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