Statistics

posted by .

1. The sociologist surveyed the households in a small town. The random variable X represents the number of dependent children in the households. The following is the probability distribution of X:
X 0 1 2 3 4
P(X) 0.07 0.20 0.38 k 0.13
(a) Find the missing probability value of k
(b) Find the mean of X
(c) Find the standard deviation of X

  • Statistics -

    a)k=1-(0.07+0.20+0.38+0.13)=0.22
    b)M(X)=0*0.07+1*0.20+2*0.38+3*0.22+4*0.13=
    =2.14
    c)M(X^2)=0*0.07+1*0.20+4*0.38+9*0.22+
    +16*0.13=5.78
    The standard deviation=
    =sqrt(M(X^2)-M(X)^2)=1.10

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. business statistics

    It has been reported that 10.3% of U.S. households do not own a vehicle, with 34.2% owning 2 vehicles, and 17.1% owning 3 or more vehicles. The data for a random sample of 100 households in a resort community are summarized in the …
  2. business statistics

    It has been reported that 10.3% of U.S. households do not own a vehicle, with 34.2% owning 2 vehicles, and 17.1% owning 3 or more vehicles. The data for a random sample of 100 households in a resort community are summarized in the …
  3. business statistics

    It has been reported that 10.3% of U.S. households do not own a vehicle, with 34.2% owning 2 vehicles, and 17.1% owning 3 or more vehicles. The data for a random sample of 100 households in a resort community are summarized in the …
  4. business statistics

    It has been reported that 10.3% of U.S. households do not own a vehicle, with 34.2% owning 2 vehicles, and 17.1% owning 3 or more vehicles. The data for a random sample of 100 households in a resort community are summarized in the …
  5. Statistics

    3. A telephone company wants to estimate the porportion of households that would purchase an additional service line if it were made available at a substantially reduced cost. A random sample of 500 households is selected and the results …
  6. statistic

    A survey of households in a small town showed that in 500 of 1,200 sampled households, at least one member attended a town meeting during the year. Using the 95% level of confidence, what is the confidence interval for the proportion …
  7. statistics

    How many TV's are there in your household?
  8. Delta

    According to a previous report, 25% of households had some type of high-speed Internet connection. Suppose 8 households are selected at random and the number of households with high-speed Internet is recorded (a) Find the probability …
  9. Math

    In a survey of 380 households regarding the ownership of VCRs and DVD players, the following data was obtained: ​ 350 households own one or more VCRs. ​180 households own one or more VCRs and one or more DVD players. ​13 …
  10. Stats

    According to a previous​ report, 15​% of households had some type of​ high-speed Internet connection. Suppose 12 households are selected at random and the number of households with​ high-speed Internet is recorded.​ (a) Find …

More Similar Questions