What is the answer to -4+4?
2 answers:
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Answer:
H0: μ ≤ 34
H1: μ > 34
The z-test statistic is ≈ 1.8
The critical z-score is 1.28
we fail to reject the null hypothesis H0: μ ≤ 34
Step-by-step explanation:
H0: μ ≤ 34
H1: μ > 34
The z-test statistic is calculated using the formula:
z= where
- X is the average class size found in the sample (35.6)
- M is the mean according to the null hypothesis (34)
- s is the standard deviation for class size (9)
then z= ≈ 0.18
The critical z-score is 1.28 for α=0.10 (one tailed)
Because the test statistic is less than the critical value, do not reject the null hypothesis.
Given:
Total number of coins (Quarters and dimes) = 60
Total amount = $12.45
To find:
The number of quarters and dimes.
Solution:
Let x be the number of quarters and y be the number of dimes.
We know that,
1 quarter = 0.25 dollar
1 dime = 0.10 dollar
Total coins: ...(i)
Total amount: ...(ii)
From (i), we get
...(iii)
Putting this value in (ii), we get
Divide both sides by 0.15.
Putting x=43 in (iii), we get
So, the number of quarters is 43 and the number of dimes is 17.
Therefore, the correct option is b.