As described in z-distribution the answers are given below:
a) The 95% confidence interval estimate for the population mean spending by a customer on visiting salon per month is given as follows: (747, 853).
b) The sampling error at 95% confidence level is of: $35.78.
What is a z-distribution ?
The normal distribution with a mean of 0 and a standard deviation of 1 is referred to as the standard normal distribution (also known as the Z distribution) (the green curves in the plots to the right). It is frequently referred to as the bell curve since the probability density graph resembles a bell.
solution:
The bounds of the confidence interval are given as follows:
In which:
is the sample mean.
z is the critical value.
n is the sample size. is the standard deviation for the population.
The parameters for this problem are given as follows:
Hence the lower bound of the interval is of:
800 - 200 x 1.96/square root of 55 = 747.
The upper bound of the interval is of:
800 + 200 x 1.96/square root of 55 = 853.
The sampling error for a sample size of 120 is calculated as follows:
200 x 1.96/square root of 120 = $35.78.
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Answer:
Return on equity (ROE) = profit margin × asset turnover × financial leverage
Step-by-step explanation:
Return on equity (ROE) = profit margin × asset turnover × financial leverage
Which can be written as:
ROE = (net income÷ sales) × (sales ÷ total assets) × (total asset ÷ average shareholder equity)
The probability that the manufacturing unit has carbon emissions beyond the permissible emission level is 0.2975
Given that the probability that carbon emissions from the company’s factory exceed the permissible level is 35% and the accuracy of the test is 85%.
The possibility of an event or outcome happening contingent on the occurrence of a prior event or outcome is known as conditional probability. The probability of the prior event is multiplied by the current likelihood of the subsequent, or conditional, occurrence to determine the conditional probability.
Event A: The given Carbon emission beyond to the given permissible emission level.
Event B: Test predicts this.
To get the probability of this problem, first we need to divide by 100 the given values.
A=35/100
A=0.35
The probability of event A is P(A)=0.35
And the probability is P(B|A)=85/100=0.85
Now, we will use the conditional probability formula, we get
P(B|A)=P(A∩B)/P(A)
0.85=P(A∩B)/0.35
P(A∩B)=0.85×0.35
P(A∩B)=0.2975
Hence, the probability that the manufacturing unit has carbon emissions beyond the permissible emission level and the test predicts is0.2975.
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Answer:
a. 32 ft²
Step-by-step explanation:
Given:
L = 3 ft
W = 2 ft
H = 2 ft
Required:
Surface Area of the box
SOLUTION:
Surface area = 2LW + 2LH + 2HW
Plug in the values
Surface area = 2(3*2) + 2(3*2) + 2(2*2)
SA = 12 + 12 + 8
SA = 32 ft²