ICS Part 2 Statistics Chapter 12 Online Test

A range of values within which the population parameter is expected:

• Confidence interval A
• Confidence coefficient B
• Confidence limits C
• Level of significance D

The difference of upper and lower limits of confidence interval measures the

• level of significance A
• level of confidence B
• interval C
• precision D

The following statistic are unbiased estimators:

• The Sample mean A
• S² = Σ(X - X)²/n-1 B
• The sample proportion C
• All the above D

Small sample has less than

• 50 values A
• 45 values B
• 30 values C
• 35 values D

If (1-α) is increased, the with of a confidence interval is:

• Decreased A
• Increased B
• Constant C
• Same D

100(1-α)% confidence interval for population proportion of success,&=nbsp;π is

• P (L <μ < U) = 1 - α A
• P (L <σ < U) = 1 - α B
• P (L <π< U) = 1 - α C
• P (L <P&=nbsp;< U) = 1 - α D

If mean of the sampling distribution is equal to the parameter then the estimator will be

• biased A
• consistent B
• sufficient C
• unbiased D

A single value used to estimate a population value is called:

• Interval estimate A
• Point estimate B
• Confidence interval C
• Level of confidence D

Statistical inference has two branches namely:

• Level of confidence and degrees of freedom A
• Biased estimator and unbiased estimator B
• Point estimate and interval estimate C
• Estimation of parameter and testing of hypothesis D

If the observations are paired and the number of pairs is n, then the number of degree of freedom is equal to

• n A
• n - 1 B
• 2n C
• 2n - 1 D

The precision can be increased by  ---------------- the sample size

• increasing A
• decreasing B
• changing C
• ignoring D

Estimate is the observed value of an:

• Unbiased estimator A
• Estimation B
• Estimator C
• Interval estimation D

The endpoints of a confidence interval are called:

• confidence coefficient A
• Confidence limits B
• Error of estimation C
• Parameters D

• best estimators A
• biased estimators B
• unbiased estimators C
• normal estimators D

If 1-α = 0.90, the value of Z_a/2 is:

• 1.645 A
• 1.96 B
• 2.326 C
• 2.575 D

Large sample contains more than

• 5 values A
• 10 values B
• 20 values C
• 30 values D

If population proportion (P) is unknown, the standard error of the sample proportion (p) can be estimated by the formula

• 
  A
• 
  B
• 
  C
• 
  D