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
#LearnwithBrainly
14 plus 40 equals 54 divided by 3 equals 18
The answer is 18
Answer:
Where is the picture for the question?
Let the speed of the water current be v.
total travel time = time to go upstream + time to return downstream to the starting point
Hence, 8 = time in hours = 6 / (4-v) + 6 / (4 +v) = 6*8/(16-v^2)
Hence, 16 - v^2 = 6, or v^2 = 10 or v = √10 miles / hour