Answer:
rate of the boat in still water: 81 km/h
rate of the current: 18 km/h
Step-by-step explanation:
<h2><u>
Answer with explanation</u>
:</h2>
Let
be the distance traveled by deluxe tire .
As per given , we have
Null hypothesis : 
Alternative hypothesis : 
Since
is left-tailed and population standard deviation is known, thus we should perform left-tailed z-test.
Test statistic : 
where, n= sample size
= sample mean
= Population mean
=sample standard deviation
For
, we have

By using z-value table,
P-value for left tailed test : P(z≤-2.23)=1-P(z<2.23) [∵P(Z≤-z)=1-P(Z≤z)]
=1-0.9871=0.0129
Decision : Since p value (0.0129) < significance level (0.05), so we reject the null hypothesis .
[We reject the null hypothesis when p-value is less than the significance level .]
Conclusion : We do not have enough evidence at 0.05 significance level to support the claim that t its deluxe tire averages at least 50,000 miles before it needs to be replaced.
In order to write 4/6 as 2/3 we would break apart pieces and to write 4/6 as 8/12 we would combine pieces.
<h3>What are fractions?</h3>
A fraction is a quantity that is not a whole number. In maths, a fraction usually has a numerator and a denominator. The numerator is the number above. While the denominator is the number below.
In order to write 4/6 as 2/3 we have to express in its simplest form. This means that you have to divide 4/6 by 2. In order to write 4/6 as 8/23, multiply 4/6 by 2.
To learn more about multiplication of fractions, please check: brainly.com/question/1114498
Answer: Janelle is 1/2 below sea level, the altimeter should read -1/2 feet
Step-by-step explanation:
Answer: C
Step-by-step explanation: You want to find the square root of each number given. The square root of 400 is 20, and the square root of 100 is 10