A sample of 25 one-year-old girls had a mean weight of 24.1 pounds with a standard deviation of pounds. Assume that the population of weights is normally distributed. A pediatrician claims that the standard deviation of the weights of one-year-old girls is less than pounds. Do the data provide convincing evidence that the pediatrician's claim is true

Paedtricians claim isn't true.

Step-by-step explanation:

The hypothesis :

H0 : σ = 7

H0 : σ > 7

The test statistic ; χ² :

χ² = [(n - 1) * s²] ÷ σ²

n = 25 ; s = 4.3, σ = 7

χ² = [(25 - 1) * 4.3²] ÷ 7²

χ² = [(24 * 4.3²] ÷ 49

χ² = 443.76 / 49

χ² = 9.056

At α = 0.01 ; critical value = 42.980

Since critical value > test statistic, we fail to reject the null, H0.

5x+40

5(x + 8)

7x - 49

7(x - 7)

18x + 9

9(2x + 1)

15x - 10

5(3x - 2)

step-by-step explanation:

for number one all you have to do is factor 5 out of 5x + 40

for number 2 factor 7 out of 7x - 49

for number three factor 9 out of 18x + 9

for number four factor 5 out of 15x - 10