Answer:
5.2 Minutes, or 5 minutes and 12 seconds
Step-by-step explanation:
You can solve this problem by working backward. Since our number gets smaller by a 1/10 or 0.1, in order to work backward we must multiply 3.60 by 10/9, since one tenth has been taken away already. When we do this, we get 4.0. When we add 1.2 minutes to that, we get a final answer of 5.2 minutes, or 5 minutes and 12 seconds.
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
Learn more:
You can learn more about z-score in brainly.com/question/7207785
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4 neither of them are functions because the x repeats itself