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7.3 kg of copper sits at a temperature of 38 degrees F. How much heat is required to raise its temperature to 865 degrees F? The specific heat of copper is 385 J/kg- degree C. Submit your anwser in exponential form.
In how many different ways can 3 elements be selected in order from a set with five 10 when repetition is allowed?
A box of mass 2.00kg is released from rest at the top of a plane inclined 15.3º above horizontal. The coefficient of kinetic friction is 0.22. What will be the speed of the mass after sliding 4.2 m along the plane? Round to the nearest hundredth.
Block A rests on top of block Bas shown in (Figure 1). The table is frictionless but there is friction (a horizontal force) between blocks A and B. Block B has mass 6.00 kg and block A has mass 2.00 kg. If the horizontal pull applied to block B equals 12.0 N, then block B has an acceleration of 1.80 m/s2
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5. A class in statistics contains 10 students, 3 of whom are 19, 4 are 20, 1
is 21, 1 is 24, and 1 is 26. Let X be the average age of the 2 randomly
selected students and derive the probability function for X.
6. A man has four keys in his pocket and, since it is dark, cannot see which
is his door key. He will try each key in turn until he finds the right one.
Let X be the number of keys tried (including the right one) to open the
door. What is the probability function for X?
7. Suppose a fair die is tossed two times. Let X be the larger of the two
faces that appear. Find px(k).
8. Suppose a particle moves along the x-axis beginning at 0. It moves one
integer step to the left or right with equal probability. What is the probability
function of its position after four steps?
9. Five cards are dealt from a standard 52-card deck. Let Y be the number
of red cards that are dealt. What is the probability function for Y ?
1.5 mol of kcio3 decomposes. How many grams of O2 will be produced
22. For a chi-square distribution,find x2\alpha
such that
a) P(X2 > x2\alpha) = 0:99 when df = 4;
b) P(X2 > x2\alpha) = 0:025 when df = 19;
c) P(37.652 < X2 < x2\alpha) = 0:045 when df = 25.
23. Find
a) t0.025 when df = 14
b) -t0.10 when df = 10
c) t0.995 when df = 7.
24. Find
a) P(T < 2:365) when df = 7;
b) P(-1.356 < T < 2.179) when df = 12;
c) P(T > 1.318) when df = 24;
d) P(T > -2.567) when df = 17.
25. For an F-distribution, find the value of f such that
a) P(F > f) = 0:05 when df1 = 4 and df2 = 9;
b) P(F > f) = 0:05 when df1 = 9 and df2 = 4;
c) P(F < f) = 0:95 when df1 = 5 and df2 = 8;
d) P(f1 < F < f2) = 0:90 when df1 = 3 and df2 = 9.
On analysis of ammonium salt of alkanoic acid give 60.5% of carbon, 6.5% of hydrogen. If 0.309g of the salt yielded 0.0313g of Nitrogen. Determine the empirical formula of the salt.
18. The lengths of fully-grown scorpions of a certain variety have a mean of 1.96 inches and standard deviation of 0.08 inch. Assuming that the distribution of these lengths has roughly the shape of a normal distribution, find what percentage of these scorpions have a length of
a) 2.20 inches or more;
b) at least 1.80 inches.
19. With reference to Exercise 18, above what value would we find the longest 6 percent of these scorpions?
20. The distribution of the IQ's of the 4,000 employees of a large company has a mean of 104.5, a standard deviation of 13.9, and its shape is roughly that of a normal distribution. Given that a certain job requires a minimum IQ of 95 and bores those with an IQ over 110, how many of the company's employees are suitable for this job on the basis of IQ alone?
21. For a chi-square distribution, find
a) x20.025 when df = 15;
b) x20.01 when df = 7;
c) x20.05 when df = 24
15. The grapefruits grown in a large orchard have a mean weight of 18.2 ounces with a standard deviation of 1.2 ounces. weights of these grapefruits has roughly the shape of a normal distribution, what percentage of the grapefruit weigh
a) less than 16.1 ounces;
b) more than 17.3 ounces;
c) anywhere from 16.7 to 18.8 ounces?
16. With reference to Exercise 15, find
a) the weight above which we will find the heaviest 15% and 75% of the grapefruits;
17. A manufacturer needs coil springs that can stand a load of at least 20.0 pounds. Among two suppliers, Supplier A can supply coil springs that, on the average, can stand a load of 24.5 pounds with a standard deviation of 2.1 pounds, and Supplier B can supply coil springs that, on the average, can stand a load of 23.3 pounds with a standard deviation of 1.6 pounds. distributions of these loads can be apprx with a normal distributions, determine which of the two suppliers can provide the manufacturer with the smaller percentage of unsatisfactory coil springs.
#339914 on Dec 2023