Answer:
Lower limit = 1007.95 cm/s
Upper limit = 1142.05 cm/s
Step-by-step explanation:
We have to calculate a 95% CI with population's standard deviation known.
The sample is size n=60, with mean M=1075.
The confidence interval can be expressed as:

For a 95% CI, the value of z=1.96.

No.
It's not smaller either.
0.5 is exactly equal to 9/18 .
Both of them are different ways to write "one half".
Answer:
121.50
Step-by-step explanation:
Let x be the earnings
2x+10 = 253
Subtract 10 from each side
2x+10-10 = 253-10
2x = 243
Divide by 2
2x/2 = 243/2
x = 121.50