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.

2 & 7

step-by-step explanation:

he climbs 300 ft/hr at a constant rate. the peak is at 1,500 ft.

when going up, he reaches 600 ft in 2 hours. remember, that he is going in a constant rate. divide 600 with 300:

600/300 = 2

assuming that he takes the same route back (meaning that it's a 1500 ft route back, you can solve.

note also that you are solving when he gets back to 600 ft after he reaches the peak.

first, find the amount of hours it takes to get up the peak. divide the total amount (1500), with the ft/her (300) to get the amount of hours (x):

1500/300 = x

x = 5

it takes jamie 5 hours to get up. now, he is returning down, and reaches 600 (his current destination). remember that he climbs at a constant 300 ft/hr. divide 600 with 300:

600/300 = x

x = 2

now add the two numbers together.

x = 5 + 2 = 7

jamie takes 7 hours to go up the mountain and reach his current position when descending.

(total amount/constant rate) = (time).

remember that it is a constant rate, so in total, when he gets back down the mountain, it will take the same amount of time as when he goes up. the total amount for the round trip is: 5 + 5 = 10.

~

its 60

4 x 12 = 48

3 x 4 = 12

48 + 12 = 60

yeeeet