What is the unit rate of 42 dollars for 3 books?
1 answer:
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Answer:
Option A.) 20 pounds of walnuts and 25 pounds of almonds is correct.
Step-by-step explanation:
i) let x be the the number of pounds of almonds
ii) let y be the number of pounds of walnuts
iii) therefore x + y = 45 pounds of the mixture
iv) 1.2x + 0.75y = 1.00 45 = 45
v) Multipling equation in iv) by 4 we get
4.8x + 3y = 180
vi) multiplying equation in iii) by 3 we get
3x + 3y = 135
vii) subtracting equation vi) from equation v) we get 1.8x = 45
ix) therefore we get x = 45/1.8 = 25 pounds of almonds
x) therefore 25 + y = 45 .... substituting value of x from ix) in iii) we get
therefore y = 20 pounds of walnuts
Therefore option A.) 20 pounds of walnuts and 25 pounds of almonds is correct.
Answer:
a)
And we can find this probability with this difference:
And using the norma standard distribution or excel we got:
b)
And using the complement rule we got:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Part a
Let X the random variable that represent the variable of interest of a population, and for this case we know the distribution for X is given by:
Where and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability with this difference:
And using the norma standard distribution or excel we got:
Part b
For this case we want this probability:
And we can use the z score and we got:
And using the complement rule we got: