Select the correct answer from each drop-down menu. A self-service car wash charges $4 for the initial 5 minutes plus an additio
2 answers:
Answer: For
Nick does not has enough money to follow this recommendation.
Step-by-step explanation:
Given: A self-service car wash charges $4 for the initial 5 minutes plus an additional $0.75 for each minute after that.
Let y be the cost for car wash for m minutes then
such that at m= 5 , y=4 which is the cost for car wash (dollars) for first 5 minutes.
Also, A car enthusiast magazine recommends spending at least 15 minutes to properly wash a car.
For
But Nick has $10 which is less than $11.5, so he does not has enough money to follow this recommendation.
Answer:
Nick needs $11.50 to wash his car for at least 15 minutes. But, he has only $10. So, he does not have enough money.
Explanation:
Given information : A self-service car wash charges $4 for the initial 5 minutes plus an additional $0.75 for each minute after that.
Let the cost for car wash for M minutes be = x
Equation forms; ; .....(1)
when M= 5, x=4 (initial 5 minute cost)
Now, we also know that one should spend at least 15 minutes to properly wash a car. So, inequality for number of minutes become
Now plugging in equation (1) we get,
This shows that Nick needs $11.50 to wash his car for at least 15 minutes. But, he has only $10. So, he does not have enough money.
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Answer:
There is an 8.38% probability that the anchor will be fired.
Step-by-step explanation:
For each resident, there is only two possible outcomes. Either they can name the news anchor on the evening news at their station, or they cannot.
This means that the binomial probability distribution will be used in our solution.
However, we are working with samples that are considerably big. So i am going to aaproximate this binomial distribution to the normal.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
Can be approximated to a normal distribution, using the expected value and the standard deviation.
The expected value of the binomial distribution is:
The standard deviation of the binomial distribution is:
Normal probability distribution
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean and standard deviation
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
When we are approximating a binomial distribution to a normal one, we have that .
In this problem, we have that:
400 city residents are going to be asked. So .
Suppose that in fact 12% of city residents could name the anchor if asked. This means that .
So,
.
They plan to fire the news anchor if fewer than 10% of the residents in the sample can do so.
What is the approximate probability that the anchor will be fired?
10% of the residents is 0.10*400 = 40 residents.
Fewer than 10% is 39 residents. So the probability that the anchor will be fired is the pvalue of Z when .
So:
has a pvalue of 0.0838. This means that there is an 8.38% probability that the anchor will be fired.