A taxi company charges passengers $1.00 for a ride, and an additional $0.30
1 answer:
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Answer:
If we compare the p value and the significance level given we see that
so we can conclude that we have enough evidence to reject the null hypothesis, and we can conclude that the true mean is higher than 1,7 entrees per order at 2% of signficance.
Step-by-step explanation:
Data given and notation
represent the mean
represent the sample standard deviation
sample size
represent the value that we want to test
represent the significance level for the hypothesis test.
t would represent the statistic (variable of interest)
represent the p value for the test (variable of interest)
State the null and alternative hypotheses.
We need to conduct a hypothesis in order to check if the mean is higher than 1.7, the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
If we analyze the size for the sample is > 30 but we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:
(1)
t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".
Calculate the statistic
We can replace in formula (1) the info given like this:
P-value
The first step is calculate the degrees of freedom, on this case:
Since is a one side test the p value would be:
Conclusion
If we compare the p value and the significance level given we see that
so we can conclude that we have enough evidence to reject the null hypothesis, and we can conclude that the true mean is higher than 1,7 entrees per order at 2% of signficance.
Answer:
B. Yes it is likely. The probability that the next 50 Sunday customers will spend an average of at least $40 is P=0.0023.
Step-by-step explanation:
<em>The question is incomplete:</em>
<em>A grocery store’s receipts show that Sunday customer purchases have a skewed distribution with a mean of $32 and a standard deviation of $20.</em>
We have to assume certain conditions to calculate the probability that the next 50 Sunday customers will spend an average of at least $40.
First, this 50 purchases are representative of the total purchases made in the store (the same as saying it is a random sample).
Second, the 10% condition: the 50 sales represent less than 10% of all purchases.
Third, the sample of 50 sales is large enough to make an approximation to the normal distribution.
If all these conditions are met, we can approximate the probabiltity that the next 50 Sunday customers will spend an average of at least $40.
We have a sampling distribution, with mean 32 (equal to the population mean) and standard deviation:
Then, we calculate the z-score
The probabilty can be calculated then as:
Answer:
a. The sample size is approximately 97 adults
Step-by-step explanation:
The given parameters are;
The number of adults surveyed, n = 174
The lowest value of the pulse rate = 39 bpm
The highest value of the pulse rate = 111 bpm
The level of confidence used for determining the sample size = 90%
The given sample mean = 3 pm of the population mean
a. The range rule of thumb states that the standard deviation is approximately one quarter (1/4) of the range
The range = 111 bpm - 39 bpm = 72 bpm
Therefore, the standard deviation, σ = 72 bpm/4 = 18 bpm
The sample size, 'N', is given as follows;
Where;
N = The sample size
z = The confidence level, 90% (z-score at 90% = 1.645)
p·q = σ² = 18² = 324
e² = 3² = 9
Therefore the appropriate sample size, N ≈ 97 adults.