The number of electrical outages in a city varies from day to day. Assume that the number of electrical outages ( x ) in the cit
y has the following probability distribution. x f (x) 0 0.80 1 0.15 2 0.04 3 0.01 The mean and the standard deviation for the number of electrical outages (respectively) are _____.
2 answers:
Answer:
0.26 and 0.577
mean =0.26
Standard deviation = 0.577
Step-by-step explanation:
x P(x) x*P(x) (x-μ)² (x -μ)²*P(x)
0 0.80 0 (0 - 0.26)² = 0.0676 0.0676*0.8 = 0.0541
1 0.15 0.15 (1 - 0.26)² = 0.5476 0.5476*0.15 = 0.0821
2 0.04 0.08 (2 - 0.26)² = 3.0276 3.0276*0.04 = 0.1211
3 0.01 0.03 (3 - 0.26)² = 7.5076 7.5076*0.01 = 0.0751
The mean μ = 0 + 0.15 + 0.08 + 0.03 =0.26
The mean μ =0.26
Variance σ² = 0.0541 + 0.0821 + 0.1211 + 0.0751 = 0.3324
Standard Deviation σ² = √σ = = 0.5765 ~ 0.577
Standard Deviation σ = 0.577
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Answer:
$108000
Explanation:
- He sold it at a discount 10%
- sale price = 100% - discount percentage
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now the price:
→ $120 000 * 90%
→ 120 000 *
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The probability that more than 3 messages will arrive during a 30-second interval is .
According to the statement
we have given that the an Exponential distribution with 7 messages arriving in a 10 second period and we have to find the probability that more than 3 messages will arrive during a 30-second interval.
So, For this purpose, we know that the
The probability is the measure of the likelihood of an event to happen. It measures the certainty of the event.
And the given information is that :
3 messages will arrive during a 30-second interval.
Then
Probability = P(X=1) + P(X=2) + P(X=3).Then
The probability become according to the exponential distribution:
And then substitute the values in it then
This is the probability.
So, The probability that more than 3 messages will arrive during a 30-second interval is .
Learn more about probability here
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