Answer:
z-score = 4.43,
It is a Good day
Step-by-step explanation:
The provided information is:
Mean = $28,286.28
Standard deviation = $1,500
Let x be the sell of department store on Tuesday.
Then, x = $34,924.62
The z-score is define as:
Thus, the Tuesday's z-score is 4.43. So this is usually good day.
Answer: $20.5
Step-by-step explanation:
Let x denotes the amount for total bill.
We are given that , Sierra left $4.50 as a tip for a waiter.
This was 18% of the bill before the tip.
We can write 18% = 0.18. [To convert percent into decimal we divide it by 100.]
Then, the tip amount = 0.18 x Total bill
So, the total bill amount = $25
Hence, her total bill before the tip= Total bill amount - Tip amount
= $25- $4.50=$20.5
Thus ,her total bill before the tip= $20.5