Tickets to a school dance are sold 10$ each . The student council spent a total of 400$ on set-up costs for the dance. The schoo
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Answer:
95% confidence intervals about the population mean is
(51.7656 , 60.2344)
Step-by-step explanation:
<u><em>Step(i)</em></u>:-
Given random sample of size 'n' =17
Given mean of the sample 'x⁻' = 56
Given standard deviation of sample 's' = 10
95% confidence intervals about the population mean is determined by
Degrees of freedom
ν = n-1 = 17-1 =16
t₀.₀₅ = 1.7459 (from t-table)
<u><em>Step(ii):-</em></u>
95% confidence intervals about the population mean is determined by
( 56 - 4.2344 , 56 + 4.2344)
<em>(51.7656 , 60.2344)</em>
<u>Conclusion:</u>-
<em>95% confidence intervals about the population mean is </em>
<em>(51.7656 , 60.2344)</em>
a = hours worked by the first mechanic
b = hours worked by the second mechanic.
since the first mechanic charges $55 per hour, then for "a" hours that'd be a total of 55*a or 55a, likewise, for the second mechanic that'd be a total charge of 80*b or 80b.
we know all hours combined are 15, so then a + b = 15.
we also know that all charges combined are $950, so 55a + 80b = 950.