Answer:
Step-by-step explanation:
Given that the sample mean for a random sample of 100 cars is 27.2 miles and assume the standard deviation is 2.4 miles.
H0: x bar = 25.9
Ha: x bar ≠ 25.9
(Two tailed test at 95% confidence)
Alpha =0.05
The hypothetical mean is 25.900
The actual mean is 27.200
The difference between these two values is 1.300
The 95% confidence interval of this difference:
From -3.462 to 6.062
t = 0.5417
df = 99
standard error of difference = 2.400
The two-tailed P value equals 0.5893
Since p >0.05 this difference is considered to be not statistically significant.
Let's call the width . Since the length is three more than the width, it is .
The area (which we know to be 70) is given by the multiplication of width and length:
To solve this equation, you can use the usual quadratic formula: given an equation , the two solutions are
which in your case becomes
So, two solutions are
Since we can't accept a negative length, we only accept the second solution.
So, the dimensions are 7 and 10
Are there any decimals? Round to one digit: 7729 expressed in 1 digit = 8x10^-3