Pepper Jamie filled up her 10 Gallon gas tank for 54.50 how much did the gas cost per gallon
1 answer:
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Answer:
4
Step-by-step explanation:
Given
x + ← substitute x = 2 +
= 2 + +
Rationalise the denominator of the fraction by multiplying the numerator/ denominator by the conjugate of the denominator.
The conjugate of 2 + is 2 -
, thus
= 2 + +
= 2 + +
= 2 + + 2 -
= 4
Answer:
confidence interval = (27.9, 28.3)
Step-by-step explanation:
Here we are given the population std deviation value as 5.7. So we can use Z critical value for finding out confidence interval.
Sample size n = 4386
Std error of sample mean =
Sample mean = 28.1
Z critical value two tailed for 98% = 2.326
margin of error = ±2.326*0.0861 =0.2003
confidence interval lower bound
=
Upper bound
=
After rounding off we get
confidence interval = (27.9, 28.3)