Answer:
Step-by-step explanation:
Hello!
So you have a new type of shoe that lasts presumably longer than the ones that are on the market. So your study variable is:
X: "Lifetime of one shoe pair of the new model"
Applying CLT:
X[bar]≈N(μ;σ²/n)
Known values:
n= 30 shoe pairs
x[bar]: 17 months
S= 5.5 months
Since you have to prove whether the new shoes last more or less than the old ones your statistical hypothesis are:
H₀:μ=15
H₁:μ≠15
The significance level for the test is given: α: 0.05
Your critical region will be two-tailed:
![Z_{\alpha /2} = Z_{0.025}= -1.96](https://tex.z-dn.net/?f=Z_%7B%5Calpha%20%2F2%7D%20%3D%20Z_%7B0.025%7D%3D%20-1.96)
![Z_{1-\alpha /2} = Z_{0.975}= 1.96](https://tex.z-dn.net/?f=Z_%7B1-%5Calpha%20%2F2%7D%20%3D%20Z_%7B0.975%7D%3D%201.96)
So you'll reject the null Hypothesis if your calculated value is ≤-1.96 or if it is ≥1.96
Now you calculate your observed Z-value
Z=<u>x[bar]-μ</u> ⇒ Z=<u> 17-15 </u> = 1.99
σ/√n 5.5/√30
Since this value is greater than the right critical value, i.e. Zobs(1.99)>1.96 you reject the null Hypothesis. So the average durability of the new shoe model is different than 15 months.
I hope you have a SUPER day!
The answer to this scatter plot question is y=1/3x-9
Answer:
2 gallons
Step-by-step explanation:
2 gallons of paint
Explanation:
If 3/4 of a gallon covers 2/5 of a wall, this means that a half of 3/4 gallons can cover 1/5 of a wall.
By knowing this, you can just make up your own expression
(the trick is to find a way to break it down to one, so you can multiply and manipulate it to save yourself some brain cells)
15
+
15
+
15
+
15
+
15
= whole wall
if
342
=
38
= amount of paint to cover 1/5 wall
then
(38)⋅5
=
38
+
38
+
38
+
38
+
38
=
158
≈
1.875
since we're talking about real life it would be 2 gallons of paint instead of 1.875 gallons to paint the whole wall
Hope this helps!
|x+y|=|x|+|y| is true because its a formula for a equation