Plz help my mom said i had to ketchup of work
1 answer:
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Step-by-step explanation:
Let n be the number of nickels that Casey has.
We are told that Megan has 4 times as many nickels as Casey has, therefore, the number of nickels that Megan has will be 4*n.
Now we will add the amounts of nickels that Casey and Megan have to find the total amount of nickels.
Therefore, the expression will represent the total number of nickels that Casey and Megan have .
Upon combining like terms we will get,
Therefore, Casey and Megan have 5n nickels.
Answer:
The sample size must be greater than 37 if we want to reject the null hypothesis.
Step-by-step explanation:
We are given that someone claims that the breaking strength of their climbing rope is 2,000 psi, with a standard deviation of 10 psi.
Also, we are given a level of significance of 5%.
Let = <u><em>mean breaking strength of their climbing rope</em></u>
SO, Null Hypothesis, :
= 2,000 psi {means that the mean breaking strength of their climbing rope is 2,000 psi}
Alternate Hypothesis, :
< 2,000 psi {means that the mean breaking strength of their climbing rope is lower than 2,000 psi}
Now, the test statistics that we will use here is One-sample z-test statistics as we know about population standard deviation;
T.S. = ~ N(0,1)
where, = ample mean strength = 1,997.2956 psi
= population standard devaition = 10 psi
n = sample size
Now, at the 5% level of significance, the z table gives a critical value of -1.645 for the left-tailed test.
So, to reject our null hypothesis our test statistics must be less than -1.645 as only then we have sufficient evidence to reject our null hypothesis.
SO, T.S. < -1.645 {then reject null hypothesis}
n > 36.99 ≈ 37.
SO, the sample size must be greater than 37 if we want to reject the null hypothesis.