One problem facing the manager of maintenance departments is when to change the bulbs in streetlamps. if bulbs are changed only when they burn out, it is quite costly to send crews out to change only one bulb at a time. this method also requires someone to report the problem and, in the meantime, the light is off. if each bulb lasts approximately the same amount of time, they can all be replaced periodically, producing significant cost savings in maintenance. suppose that a financial analysis of the lights at yankee stadium has concluded that it will pay to replace all of the light bulbs at the same time if the variance of the lives of the bulbs is less than . the lengths of life of the last 100 bulbs were recorded. what conclusion can be drawn from these data? use a 5% significance level.

yes. we do proportions in probabilities.

add an image

step-by-step explanation:

to have more of what you want like money

step-by-step explanation:

save it by not spending on unnecessary stuff and have more

step-by-step explanation: so we look at the formula un = a + (n-1)d

un is the amount of seats

n is the nth term aka row number

a is the original sequence/row number

d is the difference between each term

so in this a=22 d=6 and n can remain as n because we are simply formjng a rule

lets put these in the equation

un=22+(n-1)(6)

this is your answer to part a

however

lets double check that this is correct, we'll try putting it into the second term

un=a+(n-1)d

u2=22+(2-1)(6)

u2=22+6

u2=28

as the question said the second row has 28 seats so now we know the formula we made is correct.

as for part b

un=a+(n-1)

its asking us to find a row with 100 seats.

remember un was the amount of seata so all we do is substitute this in.

un=100 a=22 d=6

un=a+(n-1)d

100=22+(n-1)(6)

so now we simplify to find n which is the row number.

100-22=22+(n-1)(6)-22

78=(n-1)(6)

78/6=(n-1)(6)/6

13=n-1

13+1=n-1+1

14=n

so now we know that in the 14th row there is 100 seats.

hope this and that you understood! its my first time using the app or anyone out on here : p its also me to revise so a bunch! ask more questions if you dont understand ☺