Answer:
0.52763 is the probability that the time between the next two calls will be 54 seconds or less.
0.19285 is the probability that the time between the next two calls will be greater than 118.5 seconds.
Step-by-step explanation:
We are given the following information in the question:
The time between telephone calls to a cable television service call center follows an exponential distribution with a mean of 1.2 minutes.
The distribution function can be written as:

The probability for exponential distribution is given as:

a) P( time between the next two calls will be 54 seconds or less)

0.52763 is the probability that the time between the next two calls will be 54 seconds or less.
b) P(time between the next two calls will be greater than 118.5 seconds)

0.19285 is the probability that the time between the next two calls will be greater than 118.5 seconds.
Answer:

slope = 2
Step-by-step explanation:
Answer and Step-by-step explanation:
we have the following data:
Point estimate = sample mean = \ bar x = 12.39
Population standard deviation = \ sigma = 3.7
Sample size = n = 177
a) the margin of error with a 90% confidence interval
α = 1 - 90%
alpha = 1 - 0.90 = 0.10
alpha / 2 = 0.05
Z \ alpha / 2 = Z0.05 = 1,645
Margin of error = E = Z \ alpha / 2 * (\ sigma / \ sqrtn)
we replace:
E = 1.645 * (3.7 / \ sqrt177)
Outcome:
E = 0.46
b) margin of error with a 99% confidence interval
α = 1-99%
alpha = 1 - 0.99 = 0.01
alpha / 2 = 0.005
Z \ alpha / 2 = Z0.005 = 2,576
Margin of error = E = Z \ alpha / 2 * (\ sigma / \ sqrtn)
we replace:
E = 2,576 * (3.7 / \ sqrt177)
Outcome:
E = 0.72
c) A larger confidence interval value will increase the margin of error.
Answer:
B. Only 140 is an outlier
Step-by-step explanation:
To properly identify an outlier, you must first know what it is. An outlier is a number that is either a lot higher or a lot lower than the average in a set of numbers. For example, if you had a number set of 1, 3, 4, 6, and 72, you can deduce that 72 is the outlier because it's very far away compared to the other numbers in the set.
In the set that's provided, the numbers tend to range in the double digits, going up in small increments from 15 to 89. However, we can see that 140 is a lot higher than the rest of the numbers in the set, so we can assume that 140 is an outlier.