Find the sum of 7.7, 0.94, and 13
1 answer:
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Answer:
see explanation
Step-by-step explanation:
The nth term of an AP is
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Given a₅ is double a₇ , then
a₁ + 4d = 2(a₁ + 6d) , that is
a₁ + 4d = 2a₁ + 12d ( subtract a₁ from both sides )
4d = a₁ + 12d ( subtract 12d from both sides )
- 8d = a₁
The sum of n terms of an AP is
=
[ 2a₁ + (n - 1)d ] , substitute values
=
( 2(- 8d) + 16d)
= 8.5(- 16d + 16d)
= 8.5 × 0
= 0
Answer:
The minimum percentage of the commuters in the city has a commute time within 2 standard deviations of the mean is 75%.
Step-by-step explanation:
We have no information about the shape of the distribution, so we use Chebyshev's Theorem to solve this question.
Chebyshev Theorem
At least 75% of the measures are within 2 standard deviations of the mean.
At least 89% of the measures are within 3 standard deviations of the mean.
An in general terms, the percentage of measures within k standard deviations of the mean is given by .
Applying the Theorem
The minimum percentage of the commuters in the city has a commute time within 2 standard deviations of the mean is 75%.
Answer:
The mean of X is 122.5 and the standard deviation is 7.9.
Step-by-step explanation:
For each adult, there are only two possible outcomes. Either they believe that the overall state of moral values is poor, or they do not believe this. The probability of an adult believing this is independent of other adults. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The expected value of the binomial distribution is:
The standard deviation of the binomial distribution is:
In this problem, we have that:
So
The mean of X is 122.5 and the standard deviation is 7.9.