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1. The resting heart rates for a sample of individuals are normally distributed with a mean of 70 and a standard deviation of 10 Find the percentage rates of heart rates less than 60.

2. The resting heart rates for a sample of individuals are normally distributed with a mean of 70 and a standard deviation of 10 Find the percentage rates of heart rates less than 80.

3. The resting heart rates for a sample of individuals are normally distributed with a mean of 70 and a standard deviation of 10 Find the percentage rates of heart rates greater than 50.


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User Cordula
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1 Answer

4 votes

Answer:

Explanation:

Looking at the information given, the population mean and population standard deviation are known. We would apply the formula

z = (x - µ)/σ

Where

x = sample mean

µ = population mean

σ = population standard deviation

From the information given,

µ = 70

σ = 10

1) x = 60

The probability that the heart rate if an individual is less than 60 is expressed as

P(x < 60)

z = (60 - 70)/10 = - 1

Looking at the normal distribution table, the probability corresponding to the z score is 0.16

The percentage rates of heart rates less than 60 is 0.16 × 100 = 16%

2) x = 80

The probability that the heart rate if an individual is less than 80 is expressed as

P(x < 80)

z = (80 - 70)/10 = 1

Looking at the normal distribution table, the probability corresponding to the z score is 0.84

The percentage rates of heart rates less than 80 is 0.84 × 100 = 84%

3) x = 50

The probability that the heart rate if an individual is greater than 50 is expressed as

P(x > 50) = 1 - P(x ≤ 50)

z = (50 - 70)/10 = - 2

Looking at the normal distribution table, the probability corresponding to the z score is 0.23

P(x > 50) = 1 - 0.23 = 0.77

The percentage rates of heart rates greater than 50 is 0.77 × 100 = 77%

User Mayelin
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