The average price of a laptop is $965. Assume laptop prices are approximately normally distributed with a standard
deviation of $100. The least expensive 10% of laptops cost less than what amount?
• Use a TI-83, TI-83 plus, or TI-84 calculator, and round your answer to two decimal places,

Respuesta :

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Answer:

$836.8

Step-by-step explanation:

Average price = mean = $965

Standard deviation, = $100

Given that distribution is approximately normal ;

The least expensive 10% of the laptops :

We Obtain the Zscore that corresponds to P(Z ≤ 0.1) ; this means the least 10% of the laptops ;

From, a normal probability distribution table ;

P(Z ≤ 0.1) = - 1.282

We substitute this into the Zscore formula :

Zscore = (x - mean ) / standard deviation

x = price

-1.282 = (x - 965) / 100

-128.2 = (x - 965)

x = - 128.2 + 965

x = $836.8

Hence, price is $836.8