You want to estimate the mean number of sentences in a magazine advertisement. How many magazines advertisements must be included in the sample if you want to be 95% confident that the sample mean is within one sentence of the population mean

Complete question:

You want to estimate the mean number of sentences in a magazineadvertisement. How many magazine advertisements must beincluded in the sample if you want to be 95% confident that thesample mean is within 1 sentence of the population mean ? (sigma =5)

96

Step-by-step explanation:

We have level of confidence = 95%

Alpha = 1-0.95

= 0.05

Alpha/2 = 0.025

Z-alpha/2 = 1.96

E = margin of error = 1

For this question the formula to derthe sample size is given as:

n = [(Za/2 x sigma)/E]²

n = (1.96 x 5/1)²

n = 9.8²

= 96.04

So 96 magazines advertisement must be included in the sample to be 95% confident.

d) 30 units^2

area of rectangle = l × b

we know,

length = 10 unit

breadth = 3 unit

applying the formula,

= l × b

= 10 × 3

= 30 unit^2

happy to

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nswer: a   y-axis

step-by-step explanation: