Step-by-step explanation:
Mean = 81740
Standard deviation = 4590
Sample size = 15
Alpha level = 1-0.95 = 0.05
Df = 15-1 = 14
Critical value:
alpha/2 = 0.05/2 = 0.05
t0.025
t critical value = 2.145
Margin of error ME
2.145 x 4590/√15
2.145 x 4590/3.873
ME = 2542.09
Confidence interval
Lower CI = mean - ME
= 81740-2542.09
= 79197.91
Upper CI = mean + ME
= 81740+2542.09
= 84282.09
[ 79197.91, 84282.09]
B.
Using excel, exact answer for CI
Lower limit = 79198.142724212173
Upper limit = 84281.8572757827
C.
The assumptions to be made from the population are that
1. Samples are random
2. These samples are gotten from an approximately normal distribution
The length of the car is equal to 425cm! You can convert the scale to 1 cm : 25cm. Multiply 25 by 17 (the scale model car length) to get 425 cm
How much we talking like 20 dollars or something
The average speed would be 600 km/hr.
Step-by-step explanation:
Let the original speed be 'x'
Let the decreased speed be 'x-200'
Distance = 600 km
Time increased by 30 minutes
According to question, it becomes,
So, The average speed would be 600 km/hr.
