The correct answer is water
What? I don't understand what you mean...
The z-score of the sale of mobile phones on that day is 1.75
Step-by-step explanation:
The formula of z-score is z = (x - μ)/σ, where:
- x is the score
- μ is the mean
- σ is the standard deviation
∵ The mean sale was 45
∴ μ = 45
∵ The standard deviation was 4
∴ σ = 4
∵ 52 mobile phones were sold on a particular day
∴ x = 52
To find z-score of the sale of mobile phones on that day substitute the values of x, μ, and σ in the formula of z-score
∵ 
∴ 
∴ z = 1.75
The z-score of the sale of mobile phones on that day is 1.75
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Answer:
The height of the building is 
Step-by-step explanation:
see the attached figure to better understand the problem
we know that
In the right triangle ABC

we have

substitute and solve for BC


Find the height of the building
The height of the building (h) is equal to

Answer:

Step-by-step explanation:
Downtown Store North Mall Store
Sample size n 25 20
Sample mean
$9 $8
Sample standard deviation s $2 $1




Standard error of difference of means = 
Standard error of difference of means = 
Standard error of difference of means = 
Degree of freedom = 
Degree of freedom = 
Degree of freedom =36
So, z value at 95% confidence interval and 36 degree of freedom = 2.0280
Confidence interval = 
Confidence interval = 
Confidence interval = 
Hence Option A is true
Confidence interval is 