Please help me find W Z U
1 answer:
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Answer:
2 three points shots and 4 two points shots
Step-by-step explanation:
Let x be the number of three points shots.
Alexander made twice as many two points shots as three points shots, so the number of two points shots is 2x.
Amount earned in three points shots
Amount earned in two points shots
Total score
Alexander scores a total of 14 points, then
Answer:
1) The standard deviation of the sampling distribution is:
√ V(X[bar])= 0.3033
2) 95% of the values on the normal distribution are between μ ± 0.6066
3) The formula for the confidence interval is:
[284.5; 285.5]
Step-by-step explanation:
Hello!
Your study variable is
X: "score obtained on the test by an eighth-grader"
This variable has normal distribution:
X~N(μ;σ²)
Now the since the sample mean, X[bar], is obtained from n samples of the study variable, it is also a variable and has the same distribution as the original variable with the difference that is conditioned by the number of n samples from which it was calculated. So its distribution is:
X[bar]~N(μ;σ²/n)
Where E(X[bar])=μ and V(X[bar])= σ²/n
The sample information is:
n= 170100
X[bar]= 285
And the population standard deviation is known to be σ= 125.1
1) The standard deviation of the sampling distribution is:
√ V(X[bar]) = √(σ²/n) = σ/√n = 125.1/√170100 = 0.3033
2) 95% of the values on the normal distribution are between μ ± 2σ
This is μ ± 2*0.3033 = μ ± 0.6066
3) The formula for the confidence interval is:
X[bar] ± *σ/√n
285 ± 1.64 * 0.3033
[284.5; 285.5]
I hope it helps!