Answer:
a: z = -1.936
b: 0.0265
d: z < -1.645
Reject H0 if z < -1.645
Step-by-step explanation:
We are given:
H0: µ = 20
HA: µ < 20
n = 60, sample mean: 19.6, σ = 1.6
Since the alternate hypothesis has a < sign in it, it is a left tailed test. The < or > sign in the alternate hypothesis points towards the rejection region.
For a: We need to calculate the test statistic for our situation. This is done with a z-score formula for samples.
For b: we need to use the z-score table to look up the p-value for the score we calculate in part a. The p-value is 0.0265. This means that there is only about a 2.65% chance that the sample values were a result of random chance.
For d: Since the significance level is 0.05, and this is a one tailed test, we have a critical value of z < - 1.645. This means that if the z-score we calculate in part a is less than -1.645, we will reject the null hypothesis
See attached photo for all the calculations!
ANSWER
C. 7
EXPLANATION
We want to evaluate
We use the order of operations PEDMAS.
Dealing with the parenthesis first,we have
Note that:
and
Our expression now becomes:
Next, we add to get:
We finally subtract to get,
The correct answer is C
The correct answer is: [D]: " y = - 4x − 13 " .
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Explanation:
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All the answer choices given are written in "point-slope format" (also known as "slope-intercept format" — that is: " y = mx + b" .
All of the answer choices given have a slope of "-4" ; that is: "m = -4" .
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The only answer choice with the equation that passes through point
"(-3, 1)" — that is, when "x = -3, y = 1" — is:
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Answer choice: [D]: " y = - 4x − 13 " .
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In the equation: " y = - 4x − 13 " ; when "x = - 3, y = 1" .
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Given: " y = - 4x − 13 " ;
↔ - 4x − 13 = y ;
Plug in "(-3)" for "x" ; and see that "y = 1" ;
-4(-3) − 13 = y ;
12 − 13 = y = -1 ;
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So, when x = -3, y = 1 .
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The correct answer is: [D]: " y = - 4x − 13 " .
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Consider choice: [A]: " y = - 4x + 13 " ;
Substitute "(-3)" for "x" and see if "y = -1" ;
-4(-3) + 13 = y ; 12 + 13 = 25 ; NOT "-3" .
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Consider choice: [B]: " y = - 4x + 7 " ;
Substitute "(-3)" for "x" and see if "y = -1" ;
-4(-3) + 7 = y ; 12 + 7 = 19 ; NOT "-3" .
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Consider choice: [C]: " y = - 4x − 7 " ;
Substitute "(-3)" for "x" and see if "y = -1" ;
-4(-3) − 7 = y ; 12 − 7 = 9 ; NOT "-3" .
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This leaves us with "Answer choice: [D]: " y = - 4x − 13 " ; the only remaining answer choice; which we have already confirmed is correct; so we do not need to check.
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Hope this helps!
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Answer:
80%
Step-by-step explanation: