According to a commercial, 4 out of 5 dentist recommend a certain brand of toothpaste. Suppose There are 120 dentist in your area. What is the expected number of dentist who recommend the brand? What is the standard deviation? Needing assistance with calculating the standard deviation please.

Jackie bought a bag of oranges. she used 3/8 of the oranges to make orange juice. she used 1/3 of the oranges to make a fruit salad. she put 1/8 of the oranges in a bowl on the table. she put 2/12 of the oranges in the refrigerator. a) jackie left more oranges on the table than she put in the refrigerator. b) jackie used fewer oranges to make orange juice than she left on the table. c) jackie put fewer oranges in the refrigerator than she used to make the fruit salad. eliminate d) jackie used more oranges to make a fruit salad than she used to make orange juice.

Is each relation a function? if so, state whether it is one-to-one or many-to-one. 3. (-4,7), (-3,5), (1,4), (3,-8), (5,-11) 4. (-4,8), (-2,4), (0,1), (2,4), (4,8) 5. (-2, 1), (-2,3), (0,-3), (1,4), (3,1)

The ratios 3: 9, 4: 12, 5: 15, and 6: 18 are a pattern of equivalent ratios in the ratio table. which is another ratio in this pattern?