Answer:
755
Step-by-step explanation:
DeltaMath
Answer:
60,000
Step-by-step explanation:
Jane-2000
Peter-ratio of 5=25000
Marta-ratio of 7=35000
25000+35000
60000
Answer:
144 km
Step-by-step explanation:
1 hour and a half hour = 90 minutes.
In 15 minutes a car travels 24 km
In 1 minute a car travels (24÷15) = 1.6 km
In 90 minutes a car travels (90×1.6)= 144 km
Ans.- 144 km
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)
