The U.S. Geological Survey compiled historical data about Old Faithful Geyser (Yellowstone National Park) from 1870 to 1987. Let x₁ be a random variable that represents the time interval (in minutes) between Old Faithful eruptions for the years 1948 to 1952. Based on 9520 observations, the sample mean interval was x₁ = 61.2 minutes. Let x₂ be a random variable that represents the time interval in minutes between Old Faithful eruptions for the years 1983 to 1987. Based on 25,340 observations, the sample mean time interval was x₂ = 71.2 minutes. Historical data suggest that σ₁ = 8.35 minutes and σ₂ = 12.41 minutes. Let μ₁ be the population mean of x₁ and let μ₂ be the population mean of x₂.

(a) Compute a 95% confidence interval for μ₁ – μ₂. (Use 2 decimal places.)

(b) Comment on the meaning of the confidence interval in the context of this problem. Does the interval consist of positive numbers only? negative numbers only? a mix of positive and negative numbers? Does it appear (at the 95% confidence level) that a change in the interval length between eruptions has occurred? Many geologic experts believe that the distribution of eruption times of Old Faithful changed after the major earthquake that occurred in 1959.

Because the interval contains only positive numbers, we can say that the interval length between eruptions has gotten shorter.

Because the interval contains both positive and negative numbers, we can not say that the interval length between eruptions has gotten longer.  

We can not make any conclusions using this confidence interval.

Because the interval contains only negative numbers, we can say that the interval length between eruptions has gotten longer.

The U.S. Geological Survey compiled historical data about Old Faithful Geyser (Yellowstone National Park) from 1870 to 1987. Let x₁ be a random variable that represents the time interval (in minutes) between Old Faithful eruptions for the years 1948 to 1952. Based on 9280 observations, the sample mean interval was x₁ = 62.0 minutes. Let x₂ be a random variable that represents the time interval in minutes between Old Faithful eruptions for the years 1983 to 1987. Based on 24,170 observations, the sample mean time interval was x₂ = 69.6 minutes. Historical data suggest that σ₁ = 8.35 minutes and σ₂ = 12.76 minutes. Let μ₁ be the population mean of x₁ and let μ₂ be the population mean of x₂.

(a) Compute a 99% confidence interval for μ₁ – μ₂. (Use 2 decimal places.)

(b) Comment on the meaning of the confidence interval in the context of this problem. Does the interval consist of positive numbers only? negative numbers only? a mix of positive and negative numbers? Does it appear (at the 99% confidence level) that a change in the interval length between eruptions has occurred? Many geologic experts believe that the distribution of eruption times of Old Faithful changed after the major earthquake that occurred in 1959.

Because the interval contains only positive numbers, we can say that the interval length between eruptions has gotten shorter.Because the interval contains both positive and negative numbers, we can not say that the interval length between eruptions has gotten longer.    We can not make any conclusions using this confidence interval.Because the interval contains only negative numbers, we can say that the interval length between eruptions has gotten longer.

The U.S. Geological Survey compiled historical data about Old Faithful Geyser (Yellowstone National Park) from 1870 to 1987. Let x₁ be a random variable that represents the time interval (in minutes) between Old Faithful eruptions for the years 1948 to 1952. Based on 9580 observations, the sample mean interval was x₁ = 61.8 minutes. Let x₂ be a random variable that represents the time interval in minutes between Old Faithful eruptions for the years 1983 to 1987. Based on 23,000 observations, the sample mean time interval was x₂ = 69.2 minutes. Historical data suggest that σ₁ = 8.49 minutes and σ₂ = 11.78 minutes. Let μ₁ be the population mean of x₁ and let μ₂ be the population mean of x₂.(a) Compute a 99% confidence interval for μ₁ – μ₂. (Use 2 decimal places.)

(b) Comment on the meaning of the confidence interval in the context of this problem. Does the interval consist of positive numbers only? negative numbers only? a mix of positive and negative numbers? Does it appear (at the 99% confidence level) that a change in the interval length between eruptions has occurred? Many geologic experts believe that the distribution of eruption times of Old Faithful changed after the major earthquake that occurred in 1959.

Because the interval contains only positive numbers, we can say that the interval length between eruptions has gotten shorter.Because the interval contains both positive and negative numbers, we can not say that the interval length between eruptions has gotten longer.     We can not make any conclusions using this confidence interval.Because the interval contains only negative numbers, we can say that the interval length between eruptions has gotten longer.

Organism 3

Field Notes: Specimen collected from shaded area along stream in South Cumberland State Park (Grundy County, TN)
Laboratory Analysis:
Body: Large leaves emerging from underground rhizome
Size: 63cm

Chromosomal Analysis: Plant body is diploid --chromosomes number of 44

Lignin test: Positive

Cuticle: Present

Leaves: Present -- large with branched veins. Underside has sori(containing haploid spores)
Roots: Present-----branch from the inside
Stem:Present--- vascular tissue(xylem and phloem)present



Life History: Diploid sporophyte dominant generation. Haploid spores germinate into heart-shaped, haploid, gametophyte. Water required for fertilization due to flagellated sperm; no seed is produced. Diploid zygote develops into sporophyte of life ---each bearing ether megasporangia or microsporangia but not both. Insects, especially beetles, appear important in pollination   

Question: Explain which domain, kingdom and phylum you believe this plant should be classified in.

Communication: The local media features the work of your team on their nightly news. During a live interview the reporter asks you " Apparently this plant requires water for fertilization, can you explain, can you explain why"?

Response: ------------------------

Northwood Company manufactures basketballs. The company has a ball that sells for $25. At present, the ball is manufactured in a small plant that relies heavily on direct labor workers. Thus, variable expenses are high, totaling $15.00 per ball, of which 60% is direct labor cost.

Last year, the company sold 62,000 of these balls, with the following results:

1. Compute (a) last year's CM ratio and the break-even point in balls, and (b) the degree of operating leverage at last year’s sales level. (Round "Unit sales to break even" to the nearest whole unit and other answers to 2 decimal places.)

2. Due to an increase in labor rates, the company estimates that next year's variable expenses will increase by $3.00 per ball. If this change takes place and the selling price per ball remains constant at $25.00, what will be next year's CM ratio and the break-even point in balls? (Round "CM Ratio" to 2 decimal places and "Unit sales to break even" to the nearest whole unit.)

3. Refer to the data in Required (2). If the expected change in variable expenses takes place, how many balls will have to be sold next year to earn the same net operating income, $194,000, as last year? (Round your answer to the nearest whole unit.)

4. Refer again to the data in Required (2). The president feels that the company must raise the selling price of its basketballs. If Northwood Company wants to maintain the same CM ratio as last year (as computed in requirement 1a), what selling price per ball must it charge next year to cover the increased labor costs? (Round your answer to 2 decimal places.)

Selling price =

5. Refer to the original data. The company is discussing the construction of a new, automated manufacturing plant. The new plant would slash variable expenses per ball by 40.00%, but it would cause fixed expenses per year to double. If the new plant is built, what would be the company’s new CM ratio and new break-even point in balls? (Round "CM Ratio" to 2 decimal places and "Unit sales to break even" to the nearest whole unit.)

6A. If the new plant is built, how many balls will have to be sold next year to earn the same net operating income, $194,000, as last year? (Round your answer to the nearest whole unit.)

Number of balls =

6B. Assume the new plant is built and that next year the company manufactures and sells 62,000 balls (the same number as sold last year). Prepare a contribution format income statement and Compute the degree of operating leverage. (Round "Degree of operating leverage" to 2 decimal places.)

Northwood Company manufactures basketballs. The company has a ball that sells for $25. At present, the ball is manufactured in a small plant that relies heavily on direct labor workers. Thus, variable expenses are high, totaling $15.00 per ball, of which 60% is direct labor cost.

Last year, the company sold 60,000 of these balls, with the following results:

Required:

1. Compute (a) last year's CM ratio and the break-even point in balls, and (b) the degree of operating leverage at last year’s sales level.

2. Due to an increase in labor rates, the company estimates that next year's variable expenses will increase by $3.00 per ball. If this change takes place and the selling price per ball remains constant at $25.00, what will be next year's CM ratio and the break-even point in balls?

3. Refer to the data in (2) above. If the expected change in variable expenses takes place, how many balls will have to be sold next year to earn the same net operating income, $225,000, as last year?

4. Refer again to the data in (2) above. The president feels that the company must raise the selling price of its basketballs. If Northwood Company wants to maintain the same CM ratio as last year (as computed in requirement 1a), what selling price per ball must it charge next year to cover the increased labor costs?

Refer again to the data in (2) above. The president feels that the company must raise the selling price of its basketballs. If Northwood Company wants to maintain the same CM ratio as last year (as computed in requirement 1a), what selling price per ball must it charge next year to cover the increased labor costs? (Round your answer to 2 decimal places.)

5. Refer to the original data. The company is discussing the construction of a new, automated manufacturing plant. The new plant would slash variable expenses per ball by 40.00%, but it would cause fixed expenses per year to double. If the new plant is built, what would be the company’s new CM ratio and new break-even point in balls?

6. Refer to the data in (5) above.

a. If the new plant is built, how many balls will have to be sold next year to earn the same net operating income, $225,000, as last year?

b. Assume the new plant is built and that next year the company manufactures and sells 60,000 balls (the same number as sold last year). Prepare a contribution format income statement and compute the degree of operating leverage.

Northwood Company manufactures basketballs. The company has a ball that sells for $35. At present, the ball is manufactured in a small plant that relies heavily on direct labor workers. Thus, variable expenses are high, totaling $21.00 per ball, of which 60% is direct labor cost. Last year, the company sold 41,000 of these balls, with the following results: Sales (41,000 balls) $ 1,435,000 Variable expenses 861,000 Contribution margin 574,000 Fixed expenses 420,000 Net operating income $ 154,000 .

Required: 1-a. Compute last year's CM ratio and the break-even point in balls. (Do not round intermediate calculations.) 1-b. Compute the the degree of operating leverage at last year’s sales level. (Round your answer to 2 decimal places.)

2. Due to an increase in labor rates, the company estimates that next year's variable expenses will increase by $2.80 per ball. If this change takes place and the selling price per ball remains constant at $35.00, what will be next year's CM ratio and the break-even point in balls? (Do not round intermediate calculations.)

3. Refer to the data in (2) above. If the expected change in variable expenses takes place, how many balls will have to be sold next year to earn the same net operating income, $154,000, as last year? (Do not round intermediate calculations. Round your answer to the nearest whole unit.)

4. Refer again to the data in (2) above. The president feels that the company must raise the selling price of its basketballs. If Northwood Company wants to maintain the same CM ratio as last year (as computed in requirement 1a), what selling price per ball must it charge next year to cover the increased labor costs? (Do not round intermediate calculations. Round your answer to 2 decimal places.)

5. Refer to the original data. The company is discussing the construction of a new, automated manufacturing plant. The new plant would slash variable expenses per ball by 30%, but it would cause fixed expenses per year to increase by 76%. If the new plant is built, what would be the company’s new CM ratio and new break-even point in balls? (Do not round intermediate calculations. Round "Unit sales to break even" to the nearest whole unit.)

6. Refer to the data in (5) above. a. If the new plant is built, how many balls will have to be sold next year to earn the same net operating income, $154,000, as last year? (Do not round intermediate calculations. Round your answer to the nearest whole unit.) b-1. Assume the new plant is built and that next year the company manufactures and sells 41,000 balls (the same number as sold last year). Prepare a contribution format income statement (Do not round your intermediate calculations.) b-2. Compute the degree of operating leverage. (Do not round intermediate calculations and round your final answer to 2 decimal places.)