High School

We appreciate your visit to For this question use the 68 95 99 7 rule A researcher has a colony of bongo spiders in his lab There are 1200 adult. This page offers clear insights and highlights the essential aspects of the topic. Our goal is to provide a helpful and engaging learning experience. Explore the content and find the answers you need!

For this question, use the 68-95-99.7 rule.

A researcher has a colony of bongo spiders in his lab. There are 1200 adult spiders in the colony, and their weights are normally distributed with a mean of 11 grams and a standard deviation of 2 grams.

a. Sketch a normal curve and label the axis using the mean and standard deviation. Be sure to label one, two, and three standard deviations on either side of the mean.

b. Using the 68-95-99.7 rule, about what percent of spiders in the colony weigh between 7 grams and 13 grams?

c. Using the 68-95-99.7 rule, about what percent of spiders in the colony weigh less than 9 grams?

d. Approximately 68% of all the spider weights would occur between what two weight values?

e. What is the z-score of a spider in this colony that weighs 15 grams?

f. What percent of spiders in the colony weigh more than 15 grams?

Answer :

a. The mean as 11 grams and the standard deviation as 2 grams.

b. The percent of spiders that weigh between 7 grams and 13 grams is approximately 81%.

c. The percent of spiders that weigh less than 9 grams is approximately 16%.

d. The weight values between 9 and 13 grams include approximately 68% of all the spider weights.

e. The z-score of a spider that weighs 15 grams is 2.

f. The percent of spiders that weigh more than 15 grams is approximately 2.28%.

a. To sketch a normal curve, we start with a horizontal axis representing the weight of the spiders. The vertical axis represents the frequency or probability density of the weights. We label the mean as 11 grams and the standard deviation as 2 grams. Then we mark one, two, and three standard deviations on either side of the mean, which are 9, 13, 15, 7, and 5 grams, respectively.

b. To find the percent of spiders that weigh between 7 grams and 13 grams, we need to calculate the z-scores for these weights. The z-score formula is z = (x - μ) / σ, where x is the weight, μ is the mean, and σ is the standard deviation.

For x = 7, z = (7 - 11) / 2 = -2.

For x = 13, z = (13 - 11) / 2 = 1.

The area under the curve between z = -2 and z = 1 represents the percentage of spiders in this range. Using a standard normal distribution table or a calculator, we find this area to be approximately 81%.

c. To find the percent of spiders that weigh less than 9 grams, we need to calculate the z-score for this weight. For x = 9, z = (9 - 11) / 2 = -1. The area under the curve to the left of z = -1 represents the percentage of spiders that weigh less than 9 grams. Using a standard normal distribution table or a calculator, we find this area to be approximately 16%.

d. We know that approximately 68% of all the spider weights fall within one standard deviation of the mean. Therefore, the weight values between 9 and 13 grams include approximately 68% of all the spider weights.

e. To find the z-score of a spider that weighs 15 grams, we use the z-score formula as z = (x - μ) / σ. For x = 15, μ = 11, and σ = 2, we get z = (15 - 11) / 2 = 2. The z-score of a spider that weighs 15 grams is 2.

f. To find the percent of spiders that weigh more than 15 grams, we need to calculate the area under the curve to the right of z = 2. Using a standard normal distribution table or a calculator, we find this area to be approximately 2.28%. Therefore, approximately 2.28% of all the spiders in the colony weigh more than 15 grams.

To know more about percentage here

https://brainly.com/question/13729841

#SPJ4

Thanks for taking the time to read For this question use the 68 95 99 7 rule A researcher has a colony of bongo spiders in his lab There are 1200 adult. We hope the insights shared have been valuable and enhanced your understanding of the topic. Don�t hesitate to browse our website for more informative and engaging content!

Rewritten by : Barada