A 95 percent confidence interval for the mean of a population is to be constructedand must be accurate within 0.3 unit. A preliminary sample standard deviation is2.9. The smallest sample size n that provides the desired accuracy with 95 percentconfidence is:.A. 400 B. 359 C. 389 D. 253

B. 359

Step-by-step explanation:

Given that:

The margin of error (e) must be within 0.3 unit, The standard deviation (σ) = 2.9 and the the confidence level = 95% = 0.95

α = 1 =0.95 = 0.05

The z score of 0.025 corresponds to the z score of 0.0475 (0.5 - 0.025) which can be gotten from the normal probability table.

Therefore:

The formula for the margin of error is given by:

Therefore the smallest sample size (n) is 359

21.4 i did it already for s1

step-by-step explanation:

the answer for this question is : 360°

step-by-step explanation:

we have been given a triangle   we need to tell which one of these is a triangle below to map onto itself.

360° rotation is the complete rotation which eventually leads to the same figure which is given.

the correct will be, that is 360° that will cause the triangle below to map onto itself.