Nobel Dylan has determined that 25% of all its MP3 songs sales are credit sales. A random sample of 75 sales is selected.
1. What is the probability that the sample proportion will be greater than 0.34?
2. What is the probability that the sample proportion will be between 0.196 and 0.354?



Answer :

The probability that the sample proportion will be greater than 0.34 is P(Z≤1.8).

The chance of the pattern share below the regular chance is calculated via way of means of the z-check statistic of 1 pattern share. An excel feature of the same old regular distribution, NORMDIST() is used to get the desired probabilities.

Given that, Population share, p=zero.25

Sample size, n=seventy five

  • The required chance is P(^p>zero.34).
  • Now,
  • P(^p>zero.34)=1−P(^p−p√p(1−p)n≤zero.34−p√p(1−p)n)P(^p>zero.34)=1−P(Z≤zero.34−zero.25√zero.25(1−zero.25)seventy five)P(^p>zero.34)=1−P(Z≤1.8)
  • Excel feature for the above chance:
  • =NORMDIST(1.8,zero,1,1)
  • P(^p>zero.34)=1−zero.964P(^p>zero.34)=zero.036
  • The required chance is P(zero.196<^p<zero>
  • Now,
  • P(zero.196<^p<zero n)P(zero.196<^p<zero.354)=P(zero.196−zero.25√zero.25(1−zero.25)/seventy five P(zero.196<^p<zero.354)=P(−1.08 Z<2.08)P(zero.196<^p<zero.354)=P(Z>Excel feature for the above chance:
  • =NORMDIST(2.08,zero,1,1)
  • =NORMDIST(-1.08,zero,1,1)
  • P(zero.196<^p<zero P(zero.196<^p<zero.354)=zero.841>

Read more about probability;

https://brainly.com/question/28021875

#SPJ4

Other Questions