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Destiny's class packs school lunches for the local homeless shelter. They pack the same number of lunches each minute. In 6 minu

Leno4ka [110]

Make is a proportion
6/18=28/x
Cross multiply
18•28=6•x
504=6x
x=84

8 0

2 years ago

A manufacturing company produces valves in various sizes and shapes. One particular valve plate is supposed to have a tensile st

maxonik [38]

Answer:

$z=\frac{5.0611-5}{\frac{0.2803}{\sqrt{42}}}=1.413$

$p_v =2*P(z>1.413)=0.158$

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can't conclude that the average tensile strength is different from 5lbs/mm at 10% of signficance

Step-by-step explanation:

Data given and notation

$\bar X=5.0611$ represent the sample mean

$\sigma=0.2803$ represent the population standard deviation for the sample

$n=42$ sample size

$\mu_o =5$ represent the value that we want to test

$\alpha=0.1$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ 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 true mean is different from 5, the system of hypothesis would be:

Null hypothesis: $\mu = 5$

Alternative hypothesis: $\mu \neq 5$

If we analyze the size for the sample is > 30 but and we know the population deviation so is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-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:

$z=\frac{5.0611-5}{\frac{0.2803}{\sqrt{42}}}=1.413$

P-value

Since is a two sided test the p value would be:

$p_v =2*P(z>1.413)=0.158$

Conclusion

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can't conclude that the average tensile strength is different from 5lbs/mm at 10% of signficance

8 0

2 years ago

jim says that the output of the floor function is the number before the decimal point in the input. For what domain is Jim’s sta

Mila [183]

Jim’s statement is correct for all numbers greater than or equal to 0. It does not work for negative numbers. For example, the floor of –3.5 is –4, where –4 is not equal to –3, the number before the decimal point. Hope this helps!

Thanks!

-Charlie

7 0

2 years ago

Read 2 more answers

Pierce currently has $10,000. What was the value of his money five years ago if he has earned 5 percent interest each year?

tia_tia [17]

The first answer is correct, if you go back by 5% each year you will see that.

4 0

2 years ago

Read 2 more answers

Maria and Edwin have $23.00 each to spend at a book fair, where all students receive a 25% discount. They both want to purchase

Andreyy89

Maria : 26.50 - 0.25(26.50) = 26.50 - 6.625 = 19.88
19.87 + 0.10(19.87) = 19.87 + 1.99 = 21.86

Edwin : 0.75(26.50) = 19.88
1.10(19.88) = 21.86

and if they each have $ 23, then yes, they both ave enough money to buy the book. They both were correct in their calculations. Because taking 25% off, is the same as paying 75%.....and taking the discount price and subtracting 10% from that, is the same as multiplying by 110%. So they basically worked the same problem, just in a little different way...and they both ended up with the same answer

4 0

2 years ago