Search & Filtering
Suppose that a random variable X is normally distributed with a mean of 200 and a variance of
625.
Required:
a) What proportion of X-values lies between 180 and 195? (7)
b) Below what value do 33 per cent of X-values lie? (6)
c) What proportion of X-values are more than 190? (6)
d) What proportion of X-values are less than 195? (6)
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Data] = { 289, 215, 368, 251, 327, 282, 268, 322, 280, 232, 385, 301, 291, 256, 195, 311, 251, 381, 411, 293,306, 249, 249, 294, 305, 193, 333, 276, 195, 285, 251, 331, 268, 221, 251, 304, 250, 251, 387, 260, 281, 263, 283, 241, 229, 210, 234, 210, 241, 316, 241, 260, 319, 372, 250, 277, 264, 254, 245, 352 }1.1Which stem has most leaves ?1.2What is the sum of the number of leaves at the stem 28 and 29 ?
To the right of Z = 0.29 and to the left of Z = -1
You flip four coins. Let X, the random variable, be the number of heads on all four coins.
List the sample space for the experiment.
What are the possible values for x?
Is the random variable, x, continuous or discrete?
Construct a probability distribution for this experiment.
X
P(X)
Jacob's class organized a food drive he calculated the weighted mean for the average number of items collected per student
# of students 25,14,35,32,36,18
average #of items collected per student 4.4,3.0,4.8,5.5,5.5,5.0
Jacob calculated the weighted mean as follows: 4.4+3.0+4.8+5.5+5.5+5.0/6=4.7
what error did Jacob make?
what is the correct weighted mean
- Customers arrive at a local ice cream stand at an average rate of 16 per hour and follow a Poisson distribution.
a. What is the probability that two customers will arrive in the next 15 minutes?
b.What is the probability that 20 customers will arrive in the next hour?
c. What is the probability that 10 or fewer customers will arrive in the next hour?
d. What is the probability that more than 20 customers will arrive in the next hour?
1 a) i) Find how many numbers there are between 100 and 999 in which all three digits are different.
ii) Find how many of the numbers in part (i) are odd numbers greater than 700.
Plant scientists developed different varieties of corns that have a rich content of lysine which is a nutritious animal feed. A group of chicks were given this food to test the quality. The distribution of the weight gains (in grams) of these chicks are shown below:
Weight gains (in grams) Frequency
318 - 335 4
336 - 353 5
354 - 371 2
372 - 389 3
390 – 407 2
408 – 425 3
426 - 443 1
Find:
(a) the mean weight gains
(b) the median
(c) the variance for the above frequency intervals
(d) the standard deviation
In a town, the probabilities that a family owns a microwave, an air conditioner and a computer are 0.5, 0.6, and 0.8 respectively.
A)If a family is chosen at random from the town, find the probability that the family chosen owns
(i) all three items
(ii) only a microwave and an air conditioner
(iii) none of the three it
1. An appliance dealer wants to purchase a combined total of no more than 100 refrigerators, and dishwashers for inventory. Refrigerators weigh 200 pound each, and dishwashers weigh 100 pounds each. The dealer is limited to a total of 12,000 pounds for these two items. A profit of $35 for each refrigerator and $20 on each dishwasher is projected.
(a) Write out the linear programming model by identifying the constraints and the objective function from the description above.
(b) Using a scale of 2 cm to 20 pounds on both axes, construct and shade the region R in which every point satisfies all the constraints.
(c) Based on the graph obtained in (b), determine the corner points and find out the maximum number of refrigerators and dishwashers that the dealer can purchase and sold to make the profit.
