Question

The weights of broilers (commercially raised chickens) are approximately normally distributed with mean 1395 grams and standard deviation 200 grams. Use the TI-84 Plus calculator to answer the following. (a) What proportion of broilers weigh between 1160 and 1250 grams?(b) What is the probability that a randomly selected broiler weighs more than 1510 grams? (c) Is it unusual for a broiler to weigh more than 1610 grams? Round the answers to at least four decimal places.

Answer 1

a) 0.0977

b) 0.3507

c) No it is not unusual for a broiler to weigh more than 1610 grams

Explanation:

Mean = 1395 grams

Standard deviation = 200 grams. Use the TI-84 Plus calculator to answer the following.

We solve using z score formula

z = (x-μ)/σ, where x is the raw score, μ is the population mean, and σ is the population standard deviation.

(a) What proportion of broilers weigh between 1160 and 1250 grams?

For x = 1160

z = 1160 - 1395/300

= -0.78333

Probability value from Z-Table:

P(x = 1160) = 0.21672

For x = 1250 grams

z = 1250 - 1395/300

z = -0.48333

Probability value from Z-Table:

P(x = 1250) = 0.31443

The proportion of broilers weigh between 1160 and 1250 grams is

0.31443 - 0.21672

= 0.09771

≈ 0.0977

(b) What is the probability that a randomly selected broiler weighs more than 1510 grams?

For x = 1510

= z = 1510 - 1395/300

z = 0.38333

Probability value from Z-Table:

P(x<1510) = 0.64926

P(x>1510) = 1 - P(x<1510) = 0.35074

Approximately = 0.3507

(c) Is it unusual for a broiler to weigh more than 1610 grams?

For x = 1610

= z = 1610 - 1395/300

z = 0.71667

Probability value from Z-Table:

P(x<1610) = 0.76321

P(x>1610) = 1 - P(x<1610) = 0.23679

No it is not unusual for a broiler to weigh more than 1610 grams