6 In a twotailed ttest hypothesis test where alpha 01 s 17

6) In a two-tailed t-test (hypothesis test) where alpha = .01, s = 1.7, and n = 20, the critical values for t are:

A) +/- 2.09

B) +/- 2.86

C) +/- 2.53

D) +/- 1.73

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8)

For any probability distribution, the probability of any x-value occurring within any given range is equal to the area under the distribution and above that range.

TRUE OR FALSE WHY

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9)

UESTION 9

The sequence of steps in the complete decomposition of a time series is:

irregular variation analysis, seasonal analysis, trend analysis

seasonal analysis, trend analysis, irregular variation analysis

trend analysis, seasonal analysis, irregular variation

seasonal analysis, irregular variation, trend analysis

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10)

If the calculated Chi-Square statistic is less than the table value, we accept the null hypothesis.

TRUE OR FALSE

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11)

When conducting an hypothesis test, if z calculated is < z critical, you should accept the null hypothesis:

TRUE OR FALSE

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14)

The generic formula for the estimating line used in linear regression analysis is: Y’ = b₀ + b₁X

TRUE OR FALSE?

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17)

If the results of an “F-test” are statistically significant, that means for the variable being measured, the variation in one of the populations is greater than the variation in the other population.

TRUE OR FALSE

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18)

The Willow Company manufactures automobile batteries. The company has determined that the lives of its batteries are normally distributed with a mean life (µ) of 63 months with a population standard deviation () of 3 months. If someone purchases one of their batteries, what formula should they use to determine the probability that it will last less than 57 months?

= b₀ + b₁x

z   = (x - µ) ÷  

x - z( ÷ n) < µ <  x + z( ÷ n)

t =  (x - _x-bar) ÷ s/n

Solution

6. Answer is B 2.86

8. Yes as Range is difference between maximum and minimum value

9. Answer is B seasonal analysis, trend analysis, irregular variation analysis

10 True

11. False

14. True

17. True

18. C