Answer:
Z-score = 1.18
Step-by-step explanation:
The z-score measures how many standard deviations from the mean a data is
Therefore the z score is the quotient between the difference between a value and the mean and the standard deviation
Where
μ is the mean, x is a data of the population and is the standard deviation
In this case
Then the z-score is
Answer:
£110
Step-by-step explanation:
We know how much time it takes for a boiler and a radiator, and we need to know how much it will cost for 1 boiler and 4 radiators. We have an initial cost of £30, and since hes doing a boiler - which we know takes an hour - we can already add £20 for a start of £50.
Now, there are 4 radiators, that take 45 minutes each. We need to use this equation:
We divide by 60 because there are 60 minutes in an hour, and he charges by hour. So:
Now, to find out how much to charge, we need to figure out how much to add to the £50. Since it's £20 an hour, and it takes 3 hours to do the 4 radiators, we need to multiply:
Now we add our totals for a grand total of...