Answer:
15
Step-by-step explanation:
Finding total number of pupils(y)
3/y x 360°=27°
3x360°/y=27°
1080°/y=27°
1080°=27°y
1080°/27°=27°y/27°
40=y
Number of pupils who said that Maths was their favorite (z)
z/40x360°=135°
360°z/40=135°
360°z=135°x40
360°z=5400°
360°z/360°=5400°/360°
z=15
50 cm = 1/2 m
3 m ÷ 1/2 m = 6
It will take him six days.
Answer:
95% confidence interval for the mean number of months is between a lower limit of 6.67 months and an upper limit of 25.73 months.
Step-by-step explanation:
Confidence interval is given as mean +/- margin of error (E)
Data: 5, 15, 12, 22, 27
mean = (5+15+12+22+27)/5 = 81/5 = 16.2 months
sd = sqrt[((5-16.2)^2 + (15-16.2)^2 + (12-16.2)^2 + (22-16.2)^2 + (27-16.2)^2) ÷ 5] = sqrt(58.96) = 7.68 months
n = 5
degree of freedom = n-1 = 5-1 = 4
confidence level (C) = 95% = 0.95
significance level = 1 - C = 1 - 0.95 = 0.05 = 5%
critical value (t) corresponding to 4 degrees of freedom and 5% significance level is 2.776
E = t×sd/√n = 2.776×7.68/√5 = 9.53 months
Lower limit of mean = mean - E = 16.2 - 9.53 = 6.67 months
Upper limit of mean = mean + E = 16.2 + 9.53 = 25.73 months
95% confidence interval is (6.67, 25.73)
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