Answer:
99% confidence interval for the population average examination score is between a lower limit of 69.2872 and an upper limit of 82.7128.
Step-by-step explanation:
Confidence interval = mean +/- margin of error (E)
mean = 76
variance = 144
sd = sqrt(variance) = sqrt(144) = 12
n = 25
degree of freedom (df) = n - 1 = 25 - 1 = 24
confidence level (C) = 99% = 0.99
significance level = 1 - C = 1 - 0.99 = 0.01 = 1%
t-value corresponding to 24 df and 1% significance level is 2.797
E = t×sd/√n = 2.797×12/√25 = 6.7128
Lower limit = mean - E = 76 - 6.7128 = 69.2872
Upper limit = mean + E = 76 + 6.7128 = 82.7128
99% confidence interval is (69.2872, 82.7128)
Answer:
a). Nadia made a total of $825 last week in commission sales
b). The total amount Nadia in commission in 2011=$42,900
Step-by-step explanation:
Step 1
Express the amount in commission she earns from her sales as follows;
C=S×r
where;
C=commission earned
S=total value of stock sales
r=commission rate
In our case;
C=unknown
S=$7,500
r=11%=11/100=0.11
replacing;
C=11% of 7,500
C=(11/100)×7,500
C=0.11×7,500=825
Nadia made a total of $825 last week in commission sales
b). To express the total amount she made in 2011, we derive the formula below;
Total amount (2011)=Average weekly commission×number of weeks in 2011
where;
Average weekly commission=$825
number of weeks in 2011=52
replacing;
Total amount (2011)=(825×52)=42,900
The total amount Nadia in commission in 2011=$42,900
Answer:
5 minutes
Step-by-step explanation:
Do a proportion
440/75= 1760/x
cross multiply
440x=1760(75)
simplify
132000/440
We need a pic to see what is the shape lol
