The weight of oranges growing in an orchard is normally distributed with a mean
weight of 4 oz. and a standard deviation of 0.5 oz. From a batch of 2000 oranges, how
many would be expected to weight less than 5 oz., to the nearest whole number?

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Answer:

The weight of oranges growing in an orchard is normally distributed with a mean weight of 6.5 oz. and a standard deviation of 1 oz. Using the empirical rule, determine what interval would represent weights of the middle 99.7% of all oranges from this orchard

Step-by-step explanation:

bran leist ple

Answer:

1954

Step-by-step explanation:

If a continuous random variable X is normally distributed with mean μ and variance σ²:

[tex]\boxed{X \sim \textsf{N}(\mu,\sigma^2)}[/tex]

Given:

  • mean μ = 4 oz
  • standard deviation σ = 0.5 oz

First find the probability that the weight of an orange is less than 5 oz.

[tex]\text{If \;$X \sim \textsf{N}(4,0.5^2)$,\;\;find\;\;P$(X < 5)$}.[/tex]

Method 1

Using a calculator:

[tex]\implies \text{P}(X < 5)=0.977249868[/tex]

Method 2

Converting to the z-distribution.

[tex]\boxed{\text{If\;\;$X \sim$N$(\mu,\sigma^2)$\;\;then\;\;$\dfrac{X-\mu}{\sigma}=Z$, \quad where $Z \sim$N$(0,1)$}}[/tex]

[tex]x=5 \implies Z=\dfrac{5-4}{0.5}=2[/tex]

Using the z-tables for the probability:

[tex]\implies \text{P}(Z < 2)=0.9772[/tex]

To find the expected number of oranges that will weigh less than 5 oz from a batch of 2000, multiply the total number of oranges by the probability calculated:

[tex]\begin{aligned}2000 \times \text{P}(X < 5)&=2000 \times 0.977249868\\&=1954.499736\\&=1954\end{aligned}[/tex]

Therefore, 1954 oranges would be expected to weigh less than 5 oz.