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1.(1) The claim by a weight loss Company is that on average, the client will lose 10 pounds over ...

first 2 weeks. 50 people who joined the programme are sampled, their weight loss is 9 pounds with a standard deviation of 2.8 pounds. Can we conclude at the .05 level that a person joining the programme will lose less than 10 pounds?
(2) The following is a random sample of 90-day futures prices in dollars for 1 troy oz. of silver from The Wall Street Journal issues in May and June of 1997: 4.74, 4.77, 4.87, 4.91, 4.83, 4.72, 4.92, 4.86, 4.97, 4.71, 4.90, 4.93, 4.75, 4.88, 4.79, 4.83, 4.89.
Required:
a. Calculate the mean
b. Median
c. Standard deviation of the 90-day future price of silver data
(3) A mining company needs to estimate the average amount of copper ore per ton mined. A random sample of 50 tons gives a sample mean of 146,75 pounds. The population standard deviation is assumed to be 35.2 pounds.
Required:
a. Give a 95% confidence interval for the average amount of copper in the population of tons mined.
b. Give a 90% confidence interval for the average amount of coper per ton
c. Give a 99% confidence interval for the average amount of coper per ton
(4) An e-commerce Website gets 2,385 visitors on a particular day. Among these, 1790 visitors explore the products by looking at more pages at the site. Among these 1790 visitors who explore the products, 387 make a purchase.
Required:
a. If a visitor chosen at random from all those who visited the site, what is the probability that the visitor explored the products
b. If a visitor is chosen at random from all those who visited the site, what is the probability that the visitor made a purchase.
c. If a visitor is chosen at random from all those who explored the products, what is the probability that the visitor made a purchase.
d. Which of the preceding three probabilities is relevant to the design of the home page that leads to product page.

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a) A scientific theory must be able to be proven.
b) A scientific theory has been derived from known facts and always applies.
c) A scientific method should give different results depending on who performs the method.
d) Knowledge of our surroundings usually emerges through an interplay between theory and experiment.
2) The sides of a straight block are measured to 3,202 cm; 0.0012 cm and 11.2 cm, respectively. Calculate the volume of the straightening block and enter it with the correct number of value digits.
(2/0/0)
Number of words: 0
3) A 9.2 dm long and evenly thick rod rests on a support. 0.55 dm from one end, a dynamometer is hung so that the rod will hang horizontally. Then the dynamometer shows 4.4 N. How much does the bar weigh?
(1/1/0)
Number of words: 0
4) A bar AB that is homogeneous and evenly thick has a length of 2.70 m and is rotatable about an axis at A. The bar weighs 25 kg and is kept in equilibrium by a force F which has its point of attack in B. is 45 degrees. How big is the force F?
(1/1/0)
Saved!
25 * 9.82 = 245.5 N
Number of words: 6
5) A trolley rolls at a constant speed to the right. On the cart is an upward cannon that suddenly shoots a bullet. The carriage continues to the right with the same speed as before. Where does the bullet end up when it falls? For a detailed reasoning.
(1/1/1)
Number of words: 0
6) A river is 200 m wide. The water in the river flows at a speed of 2.5 m / s. A motorboat steers across the river at its maximum speed, which in stagnant water is 5.0 m / s. The boat is constantly heading perpendicular to the banks of the river. Where does the motorboat land on the other shore?
(2/0/0)
Number of words: 0
7) A ball with a mass of 2.0 hg moves at a constant speed in a circular path. The radius of the track is 1.5 m and it takes the ball 3.0 seconds to move one turn. How big is the centripetal force?
(1/1/0)
Number of words: 0
8) A bullet moves at a constant speed. Can we then safely say that the resultant of the forces acting on the bullet is zero? Motivate and discuss your answer.
(0/1/1)
Number of words: 0
9) A conductor is located between the poles of a permanent magnet. The current in the conductor goes in the direction of the plane of the paper (away from the reader). How is the force acting on the leader directed?
(1/0/0)
a) To the right of the figure
b) To the left in the figure
c) Downwards in the figure
d) Upwards in the figure
10) Protons enter horizontally from the left between two large metal plates at a speed v = 0.80 Mm / s. The plates are connected to a voltage source with the pole voltage U. Between the plates there is a homogeneous magnetic field with a flux density of 38 mT directed perpendicular to the plane of the paper. The distance between the plates is 1.5 cm. They want the protons to continue with unchanged direction and speed between the plates. Which of the plates should be connected to the positive pole of the voltage source and how large should the voltage U be?
(0/2/0)
Number of words: 0
11) The magnetic flux Φ through a 700-speed coil decreases linearly with time according to the diagram below. Calculate the voltage across the coil at time t = 1.0 ms.
12) The current in a coil with an inductance of 35 mH has a growth rate of 6.2 A / s at a given moment. What is the instantaneous value of the ems induced in the coil?

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3.5 (5 points) There is H3PO4 available in stock solution that has an assay of 77% and a density ...

cific gravity) of 1.24. What is the molarity of this solution?
Using this solution how would 1 L of 2N solution be made.
6 (5 points) H3BO3 is needed to neutralize 20 ML of a 2N solution of NaOH. How much of the acid should I put in 40 ML of the water to exactly neutralize this solution?
7 (6 points) Describe how to make the solutions below :
20% w/v Salt in water.
20% v/v alcohol in water
20% w/w NaCl in water.
8 (three points) I have 0.6 g/dl solution of NaOH. What is M? Whan is N?
9 (six points) There are 3000mL of 3M NaOH. How much of the following do I need to neutralize? (watch your M’s and N’s
a) 3M H3PO4
b) 2M H2SO4
c) 1M HCL
10 (20 points) The following solutions of NaOH are mixed together 20ML of 3N, 40mL of 2N, 60mL of 1N, 80 mL of 4N, and 100mL of 5N.
a) What is the volume and normality of the final solution?
b) How much 4M sulfuric acid would I need to neutralize?
c) How much stock solution of sulfuric acid with an assay of 77% and a specific gravity of 1.14 would I need?
d) How many grams of HCl would I have to put in a 300mL solution of HCl in water to neutralize?
11 (3 points) How much 5N solution can I make with 98 grams of H3PO4 ?
12 (5 points) How much 5N solution of H3AsO4 can I make with 57 mL of stock solution that is 84% assay and 1.14 specific gravity?
13 (5 points) If we have a 4N solution of HCl that has 0.03645g of HCl in the solution, how many microliters of solution do we have?
14 (10 points) If we have 66mL of a solution of concentrated NaOH that has an assay of 88% and a specific gravity of 1.24, how much 3N H3AsO4 can be neutralized?
15 (ten points) If I have 17 mL of a 20% w/v solution of NaOH and I want to neutralize with H2SO4 that is available in a 4% w/v solution, how much of this solution will be required.
16 (ten points)
a) I have an 12mL of Ba(Cl)2 that is 78% assay that contains 8 grams of Ba(Cl)2. What is the specific gravity?
b) How many Moles of Ba(Cl)2 are there?
c) If I have 80 grams of NaOH in a liter of solution that is of an unknown specific gravity, can I calculate molarity and what is it?
d) What is the difference between molarity and normality?
e) I have 77 ml of 77% salt in water. How much 11% can I make?

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1.AU MAT 120 Systems of Linear Equations and Inequalities Discussion

mathematicsalgebra Physics