The Acme Company manufactures widgets. The distribution of widget weights is bell-shaped. The widget weights have a mean of 40 ounces and a standard deviation of 9 ounces. Use the Empirical Rule, find a) 99.7% of the widget weights lie between and b) What percentage of the widget weights lie between 22 and 67 ounces? % c) What percentage of the widget weights lie below 49 ? %
In: Statistics and Probability
Suppose height and weight of people in a certain population are jointly normal with the mean height of 180cm and mean weigh of 80kg. The corresponding standard deviations are 5cm and 6kg, respectively, and the correlation is equal to 0.6. a) What is the percentage of people whose weight exceeds 95kg among those 185cm tall? b) What is the percentage of people whose weight exceeds 95kg among those whose height is 175cm?
In: Statistics and Probability
A genetic experiment with peas resulted in one sample of offspring that consisted of 439 green peas and 168 yellow peas.a. Construct a 90% confidence interval to estimate of the percentage of yellow peas.
b. It was expected that 25% of the offspring peas would be yellow. Given that the percentage of offspring yellow peas is not 25%, do the results contradict expectations?
a. Construct a 90% confidence interval. Express the percentages in decimal form.
In: Statistics and Probability
The salaries of managers at a distributing company revealed a mean income of $72,000 with a standard deviation of $3,000.
Using Chebyshev’s Theorem, at least what percentage of the managers $65,400 but no more than $78,600?
Using Chebyshev’s Theorem, at least what percentage of the managers earn between negative three and positive three standard deviations from the mean?
Under what conditions do you use the Chebyshev’s Theorem?
In: Statistics and Probability
A random sample of 158 recent donations at a certain blood bank
reveals that 88 were type A blood. Does this suggest that the
actual percentage of type A donations differs from 40%, the
percentage of the population having type A blood? Carry out a test
of the appropriate hypotheses using a significance level of
0.01.
State the appropriate null and alternative hypotheses.
what is the z value?
What is the p-value
In: Statistics and Probability
Bond B and Bond T both have 7% coupon rate, bond B has 3 years to maturity, bond T has 20 years to maturity. What is the percentage change of in the price of each bond if interest rate goes up by 2%? What is the percentage change if interest rate goes down by 2%? Which bond has higher interest rate risk?
In: Finance
In a neutron scattering experiment, a neutron scatters off the stationary nucleus of an atom with an atomic mass of 61 amu in a 1 dimensional, elastic collision. After the collision, what percentage of the neutron's kinetic energy was transferred to the atom? In a second neutron absorbtion experiment, a neutron is absorbed into the nucleus of an atom with an atomic mass of 62 amu. After the collision, what percentage of the neutron's kinetic energy was remains?
In: Physics
A genetic experiment with peas resulted in one sample of offspring that consisted of
445
green peas and
154
yellow peas.a. Construct a 95%
confidence interval to estimate of the percentage of yellow peas.
b. It was expected that 25% of the offspring peas would be yellow. Given that the percentage of offspring yellow peas is not 25%, do the results contradict expectations?
a. Construct a
95%
confidence interval. Express the percentages in decimal form.
In: Statistics and Probability
Plot the unemployment rate in the US from 1980-2016 (Hint: Use the FRED web site). What is the average unemployment rate in this period? What is the most recent unemployment rate in the US?
Plot the percentage change (yearly) in the unemployment rate and the percentage change (yearly) in the real GDP from 1980-2016. What is the relationship between the fluctuations in the unemployment rate and the fluctuations in the real GDP?
In: Economics
A man drops a rock into a well.
(a) The man hears the sound of the splash 2.20 s after he releases the rock from rest. The speed of sound in air (at the ambient temperature) is 336 m/s. How far below the top of the well is the surface of the water? (answer in meters)
(b) If the travel time for the sound is ignored, what percentage error is introduced when the depth of the well is calculated? (percentage)
In: Physics