Answer:
8 days
Step-by-step explanation:
On day 8, Isabella will save 256 nickels, bringing her total to 510.
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The number of nickels saved on day n is 2^n. The total is 2^(n+1)-2.
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The above can be written down from your knowledge of binary sequences. If you want a more formal development, read on.
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The number of nickels saved on day n is a geometric sequence with first term 2 and common ratio 2. The n-th term of the sequence is ...
an = a1·r^(n-1) = 2·2^(n-1) = 2^n
The sum of n terms of the sequence is ...
S = a1(r^n -1)/(r -1) = 2(2^n -1)/(2-1)
S = 2^(n+1) -2
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We want S > 500, so ...
500 < 2^(n+1) -2
502 < 2^(n+1)
251 < 2^n
log(251) < n·log(2)
n > log(251)/log(2)
n > 7.97 . . . . . . . . 8 days or more to save more than 500 nickels
Notice that 38 and 52 make a total of 90
sinA=cos(90-A)
sin38=cos52, therefore the answer is zero
Answer :
y=3/4x-6
explanation:
it is already in standard form.
2x + 2y=132
xy=1080
Let x=1080/y
2160/y + 2y=132
2y^2 - 132y +2160=0
2(y^2-66y+1080)=0
2(y-30)(y-33)=0
y=30 or y=33
(36,30) or (30,36)
So... x=30,36 and y=36,30. Either way, the answer is 30 by 36 or 36 by 30.
Considering the Central Limit Theorem, we have that:
a) The probability cannot be calculated, as the underlying distribution is not normal and the sample size is less than 30.
b) The probability can be calculated, as the sample size is greater than 30.
<h3>What does the Central Limit Theorem state?</h3>
It states that the sampling distribution of sample means of size n is approximately normal has standard deviation
, as long as the underlying distribution is normal or the sample size is greater than 30.
In this problem, the underlying distribution is skewed right, that is, not normal, hence:
- For item a, the probability cannot be calculated, as the underlying distribution is not normal and the sample size is less than 30.
- For item b, the probability can be calculated, as the sample size is greater than 30.
More can be learned about the Central Limit Theorem at brainly.com/question/16695444
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