400 products on line A are examined and 40% are found to be defective, 100 products on line B are examined and 20% are found to be defective. What is the appropriate test statistic?
In: Statistics and Probability
A 0.4 g sample of CMA was dissolved in HCL and diluted to 100 mL. A 10 mL aliquot of the sample was titrated with 25.5 mL of 0.01 M EDTA. The calcium was removed from a second 10 mL aliquot by precipitation with ammonium oxalate, and the remaining filtrate was titrated with 17.25 mL of 0.01 M EDTA.
a) Multiply the concentration (molarity) of EDTA by the volume, in liters, of EDTA added in the first titration to determine the combined amount (moles) of calcium and magnesium ions in a 10 mL CME aliquot.
b) Calculate the amount (moles) of magnesium and calcium in a 10 mL CMA aliquot.
c) determine the mass of magnesium acetate and the mass of calcium acetate in a 10.0 mL CMA aliquot. (Molar mass: Calcium acetate = 158.2 g/mole; magnesium acetate = 142.3 g/mole)
d) divide the original mass of the CMA sample by the initial solution volume, before removing aliquots, and multiply by the aliquot volume to determine the mass of CMA and a 10 ML aliquot.
e) calculate the percent composition of calcium acetate and the percent composition of magnesium acetate in CMA.
In: Chemistry
100 people enter a room that is initially at a temperature of 15 C and pressure of 1bar. Each person losses heat to the air in the room at a constant rate of 300 W at a constant temperature of 37 C. The air mass in the room is 750 Kg, remains constant and its cv = 0.79 kJ/(Kg K), cp = 1.08 kJ/(Kg K) and the gas constant is 0.287 kJ/(Kg K). Air enters the room at a temperature 25 C at a mass flow rate of 0.01 Kg/s and leaves the room at the temperature of the room and at the same mass flow rate. The pressure remains constant during this process.
a) Determine the temperature of the air in the room after 30 minutes assuming that there is no heat transfer from the room to the surroundings because it is heavily insulated.
b) Calculate the entropy production for this process assuming that the people are at a temperature of 310 K.
In: Mechanical Engineering
Calculate ΔHr° of isomerization of propene (g) into cyclopropane (g) at 100°C
In: Chemistry
A random sample of n = 100 scores is selected from a normal population with a mean of μ = 60 and a standard deviation of σ = 20. What is the probability of obtaining a sample mean greater than M = 57?
In: Statistics and Probability
In a random sample of
100
audited estate tax returns, it was determined that the mean amount of additional tax owed was
$3478
with a standard deviation of
$2555
Construct and interpret a 90% confidence interval for the mean additional amount of tax owed for estate tax returns.
The lower bound is $:
The upper bound is $:
In: Statistics and Probability
Why is 100% hexane not a good mobile phase for finding the polarity of aspirin and acetaminophen using thin layer chromatography?
In: Chemistry
An atom of 216Po decays by ? emission. If the emitted ? particle carries away 100% of the released energy as kinetic energy, how fast is it moving? The masses of an electron, an alpha particle, and several neutral isotopes are given, in terms of atomic mass units, to the right. In m/s
In: Physics
12. A standard IQ test has a normal distribution with a mean of 100 with a standard deviation of 15.
a) A score of 145 or higher on this exam is categorized in the gifted realm. What percent of people would be considered gifted? ___________
b) The people who score in the lowest 5% of the standard IQ test are considered to have “mental retardation”. What cutoff score is used to qualify for this benchmark? ___________
In: Statistics and Probability
If a random sample of 100 items is taken from a population in which the proportion of items having a desired attribute is p=0.45, what is the probability that the proportion of successes in the sample will be less than or equal to 0.49
The probability will be ____
In: Statistics and Probability