Question 3(1.5 points) According to one pollster, 40 % of people are afraid of f

Question

Question 3(1.5 points) According to one pollster, 40 % of people are afraid of flying. Suppose that a sample of size 28 is drawn. Find the value of ?; , the standard deviation of the distribution of sample proportions. Write only a number as your answer Round to two decimal places (for example: 8.21). Your Answer Answer Save Question 4 (2 points) It has been reported that 48% of teenagers play video games on their phones. A random sample of 60 teenages is drawn. Find the probability that the proportion of teenagers in the sample who play videos games on their phone is less than 0.499 Write only a number as your answer Round to 4 decimal places (for example 0.3748). Do not write as a percentage

Explanation / Answer

3)

SD(Phat) = SQRT(pq/n) = sqrt(0.40*(1-0.40)/28) = 0.09258201 = 0.09

4)

p= 0.48
n= 60

E(phat) = p 0.48
SD(phat) = sqrt(pq/n) = =SQRT(0.48*(1-0.48)/60) 0.064498062

P( X<0.499)

I know that, z = (X-mean)/(sd)
z1 = (0.499-0.48)/0.0645)
z1= 0.2946

hence,
P( X<0.499)
=P(Z<0.2946)
NORMSDIST(0.2946)
0.6159

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