50 random teenagers were asked how many hours a day they use their phones. They spent an average of 7 hours a day with a standard deviation of 1.3. Based on the results, what is a reasonable range for the true mean number of hours a teenager spends on their phone? Base your range using a 95% confidence level. a. (7, 8)

b. (7.9, 8.1)

c. (7.1, 8.9)

d. (6.6, 7.4)

exa:

)

3+11

14

step-by-step explanation:

from this example, we can see that subtracting with integers is the same as adding the opposite. we can solve using a number line or by using the saying "keep, change, change" to us solve. it is important to remember that we can subtract a negative and end up with a larger number than we started with.

the correct answer option is (2x-3)(2x+3).

step-by-step explanation:

we are given the following expression and we are to factorize it:

we are to find such factors that when multiplied they give a result of 36 (9 x 4 = 36) and when added they give a result of 0.

the two such factors of 36 are negative six and postive six.

factorizing the given expression to get:

therefore, the correct factorization of is (2x-3)(2x+3).

hey there : ) your answer would be a.

step-by-step explanation: