Question

Questions 15–17. A newspaper reported that 90% of youths use the Internet. Use this reported number as the population proportion. A random sample of 900 youth is selected. Let p be the sample proportion of youths who use the Internet. 15. The distribution of p is closest to ✓(a) normal with mean 0.9 and standard deviation 0.01 (b) normal with mean 0.9 and standard deviation 0.3 (c) binomial with mean 0.9 and standard deviation 0.01 (d) binomial with mean 0.9 and standard deviation 0.3 (e) Poisson with mean 0.9 and standard deviation 0.01. 16. The probability that more than 92% of youths use Internet is closest to (a) 0.0154 ✓ (b) 0.0228 (c) 0.0325 (d) 0.0445 (e) 0.0521 17. Another random sample of size n is selected. Suppose 10% of the times, more than 92% of youths in this sample use the Intranet. The value of n is closest to (a) 120 (b) 159 (c) 238 (d) 298 7(e) 369

Answer 1

0.9 0.1 900 O.o @nermal aith maau 0.g& std dew 0.0L p0.9, JP OP(P092)- PC= >0.92-0.9)- P(z2) 0,0228 P(P0.92) = O.10 - P(z> Q.92-0.9) P(z 0 O.2-1.29 O.02 .28 (P(z.28)0.10) >O.9.0.1 0.02 1.28 m368.64369