Answer:
(A) 0.0013
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean 
and standard deviation 
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
The probability that telephone call selected a random will last more than 15.5 min is most nearly
This is 1 subtracted by the pvalue of Z when X = 15.5.
So
has a pvalue of 0.9987
1 - 0.9987 = 0.0013
So the correct answer is:
(A) 0.0013
Answer: choice B) a35 = -118
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Explanation:
When n = 5, an = 32 as shown in the first column of the table. This means the fifth term is 32. Plug in those values to get
an = a1+d(n-1)
32 = a1+d(5-1)
32 = a1+4d
Solve for a1 by subtracting 4d from both sides
a1 = 32-4d
We'll plug this in later
Turn to the second column of the table. We have n = 10 and an = 7. Plug those values into the formula
an = a1+d(n-1)
7 = a1 + d(10-1)
7 = a1+9d
Now substitute in the equation in which we solved for a1
7 = a1+9d
7 = 32-4d+9d ... replace a1 with 32-4d
7 = 32+5d
5d = 7-32
5d = -25
d = -25/5
d = -5
This tells us that we subtract 5 from each term to get the next term.
Use this d value to find a1
a1 = 32-4d
a1 = 32-4*(-5)
a1 = 32+20
a1 = 52
The first term is 52
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The nth term formula is therefore
an = 52 + (-5)(n-1)
which simplifies to
an = -5n + 57
To check this result, plug in n = 5 to find that a5 = 32. Similarly, you'll find that a10 = 7 after plugging in n = 10. I'll let you do these checks.
--------------
Replace n with 35 to find the 35th term
an = -5n + 57
a35 = -5(35) + 57
a35 = -175 + 57
a35 = -118
Step-by-step explanation:
coefficient of x is 17
coefficient of y is -5
coefficient of constant term: 3 + 19 + 10 = 32
Answer:
The population will reach 34,200 in February of 2146.
Step-by-step explanation:
Population in t years after 2012 is given by:
In what month and year will the population reach 34,200?
We have to find t for which P(t) = 34200. So
Solving a quadratic equation:
Given a second order polynomial expressed by the following equation:
.
This polynomial has roots 
such that 
, given by the following formulas:
In this question:
So 
Then
We only take the positive value.
134 years after 2012.
.14 of an year is 0.14*365 = 51.1. The 51st day of a year happens in February.
So the population will reach 34,200 in February of 2146.
Answer:
1. 11t
2.7w+28
3. 2c+11
4. 8n
5. 10r+15
6. 24−8g
7. 17d−9
8. 8g+7z
9. 23b
10. 2rs+1
11. 9f+9g
12. 4x+y
13. 21a+14
14. 21a+14
15. 6−3k
16. 18n+36
17. 9s+3t
18. 8a−12b
19. 11m+n
20. 2+6z
21. 8x+6y
22. 7hg−7
23. 4st+5
24. 2r+17
25. 7w+6
26. 3(c+2)
27. 8f−4g
28. 2+8q+3r
Step-by-step explanation:
there you go, sorry it took so long
